Chimney denitration discharge system
Through the use of ammonia water and tail gas in the chimney denitrification discharge system, the high cost and complexity of existing denitration technology is solved, and the efficient absorption of pollutants in the tail gas and the effective recycling of ammonia gas in the tail gas.
Patent Information
- Application Number
- CN202420310644.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-02-20
AI Technical Summary
The existing coal-fired boiler denitrification technology has problems such as high investment and operation costs, easy deactivation and difficulty in regeneration of catalysts, and may cause secondary pollution. The system is complex, which brings management and economic pressure to the operating company.
Design a chimney denitrification discharge system. By using ammonia water in the absorption tower for atomization and exhaust gas, use ammonia water to react with NO, NO2, SO2, and CO2 in the tail gas, and avoid ammonia via cycle use and centralized treatment. emission.
The efficient absorption of NO, NO2, SO2, and CO2 in the tail gas is realized, reduced ammonia emissions, simplified the system structure, reduced operating costs, and effectively solved the complexity and high cost of denitration technology.
Smart Images
Figure CN222400919U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of chimney tail gas treatment, in particular to a chimney denitrification emission system. Background Art
[0002] Coal-fired boilers emit large amounts of SO2, nitrogen oxides (NOx) and CO2 gases. SO2 and NOx are the main components of air pollution and are also the main substances that form acid rain and photochemical smog. Greenhouse gases such as CO2 cause greenhouse effects and other environmental problems that not only destroy the ecosystem but also endanger human health. The economic and social risks and significant losses brought about by these environmental problems have undoubtedly become a major issue related to the sustainable development of my country's economy and even the harmony and stability of society.
[0003] At present, desulfurization technology is becoming increasingly mature in China, but denitrification technology still has room for improvement. For the control of SO2, the more mature technology is the limestone gypsum method, the system operates stably, and the removal efficiency can reach more than 95%. For the control of NOx, the selective catalytic reduction method (SCR) is often used, and the removal efficiency can reach more than 90%, but it has problems such as high investment and operating costs, easy deactivation and difficulty in regeneration of catalysts, and possible secondary pollution. At present, the combination technology of wet flue gas desulfurization (FGD) and NH3 selective catalytic reduction denitrification (SCR) is commonly used for desulfurization and denitrification of domestic coal-fired boilers. Although the desulfurization and denitrification efficiency of this technology is high, the system is complex, and the investment and operating costs are high, which puts considerable pressure on the operating company both in terms of management and economy. In view of the above problems, the utility model provides a solution. Utility Model Content
[0004] The utility model aims to provide a chimney denitration emission system.
[0005] The above technical objectives of the utility model are achieved through the following technical solutions:
[0006] A chimney denitrification emission system comprises an absorption tower, an exhaust gas inlet pipe and a straight-discharge chimney, wherein the straight-discharge chimney is located at the top of the absorption tower, the exhaust gas inlet pipe is connected to an exhaust gas distributor installed at the bottom of the absorption tower and above the liquid, a gas distributor is arranged above the exhaust gas distributor, the gas distributor is connected to an external oxidation fan through a pipeline, a spray layer is arranged above the gas distributor, a circulating spray layer and a demister 1 are arranged above the spray layer, a demister 2 is arranged above the demister 1, the spray layer is composed of a plurality of atomizing nozzles, The spray layer is connected to the ammonia storage device through an ammonia feed pipe, and a pressure pump is installed on the ammonia feed pipe. The circulating spray layer is also composed of multiple atomizing nozzles. The circulating spray layer is connected to the bottom of the absorption tower through a circulating pipe. Solenoid valve 1, a circulating pump and solenoid valve 2 are installed in sequence on the circulating pipe from the liquid outlet end to the circulating spray layer connection end. A sewage branch is provided on the circulating pipe between the solenoid valve 1 and the circulating pump, and a sewage valve is installed on the sewage branch. A liquid replenishment branch is provided on the circulating pipe between the circulating pump and the solenoid valve 2, and a water replenishment valve is installed on the liquid replenishment branch.
[0007] Furthermore, the spray layer is provided with multiple layers.
[0008] Furthermore, a circulating spray layer is provided above and below the demister 1.
[0009] Furthermore, the first demister is a flat plate demister, and the second demister is a tube bundle demister.
[0010] Furthermore, a smoke cyclone plate is installed in the straight exhaust chimney.
[0011] Furthermore, an air release valve is installed on the branch of the air inlet pipe where the oxidation blower is installed.
[0012] Furthermore, the exhaust gas distributor is arranged to have an outlet direction upward, and the gas distributor is arranged to have an outlet direction downward.
[0013] In summary, the utility model has the following beneficial effects: the utility model atomizes the ammonia water and fully contacts and reacts with the exhaust gas, gradually absorbs NO, NO2, SO2 and CO2 in the exhaust gas, and at the same time, after recycling the ammonia water, centrally collects and processes it to avoid ammonia emissions and effectively realize chimney denitrification emissions. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0015] In the figure, 1. absorption tower; 2. tail gas inlet pipe; 3. tail gas distributor; 4. oxidation fan; 5. vent valve; 6. gas distributor; 7. solenoid valve 1; 8. drain valve; 9. circulation pump; 10. water supply valve; 11. circulation pipe; 12. ammonia feed pipe; 13. booster pump; 14. spray layer; 15. solenoid valve 2; 16. circulation spray layer; 17. demister 1; 18. demister 2; 19. flue gas cyclone plate; 20. direct exhaust chimney. DETAILED DESCRIPTION
[0016] The utility model is further described in detail below in conjunction with the accompanying drawings, and the technical solutions in the embodiments of the utility model are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0017] like Figure 1 As shown, a chimney denitrification emission system comprises an absorption tower 1, an exhaust gas inlet pipe 2 and a straight-discharge chimney 20, wherein the straight-discharge chimney 20 is located at the top of the absorption tower 1, and the exhaust gas inlet pipe 2 is connected to an exhaust gas distributor 3 installed at the bottom of the absorption tower 1 and above the liquid, and a gas distributor 6 is arranged above the exhaust gas distributor 3, and the gas distributor 6 is connected to an external oxidation fan 4 through a pipeline, and a spray layer 14 is arranged above the gas distributor 6, and a circulating spray layer 16 and a demister 17 are arranged above the spray layer 14, and a demister 2 18 is arranged above the demister 17, and the spray layer 14 is a disc-shaped structure composed of a plurality of atomizing nozzles, and the spray layer 14 is connected to the ammonia feed pipe 12 through the ammonia feed pipe 12. A water storage device is connected, a pressure pump 13 is installed on the ammonia feed pipe 12, the circulating spray layer 16 is also composed of a plurality of atomizing nozzles, the circulating spray layer 16 is connected to the bottom of the absorption tower 1 through a circulating pipe 11, and a solenoid valve 1 7, a circulating pump 9 and a solenoid valve 2 15 are installed in sequence on the circulating pipe 11 from the liquid outlet end to the circulating spray layer connection end, a sewage branch is provided on the circulating pipe 11 between the solenoid valve 1 7 and the circulating pump 9, a sewage branch is installed on the sewage branch, and the sewage after the reaction is discharged from the sewage branch, a liquid replenishment branch is provided on the circulating pipe 11 between the circulating pump 9 and the solenoid valve 2 15, and a water replenishment valve 10 is installed on the liquid replenishment branch, and new water can be replenished into the whole system from the water replenishment valve 10.
[0018] The main reactions of atomized ammonia water in absorbing NO and NO2 in the exhaust gas are:
[0019] NO+O=NO2;
[0020] NO2+NO+NH3=NH4NO3+NH4NO2;
[0021] NH3+HNO3=NH4NO3;
[0022] NH3+HNO2=NH4NO2;
[0023] The main absorption reaction of SO2 in tail gas is:
[0024] SO2+NH3+H2O=NH4HSO3;
[0025] SO2+2NH3+H2O=(NH4)2SO3;
[0026] (NH4)2SO3+H2O+SO2=2(NH4)2SO3;
[0027] (NH4)2SO3+SO2=(NH4)2SO3;
[0028] At the same time, ammonia can also absorb CO2 in the exhaust gas:
[0029] CO2+H2O+2NH3=(NH4)2CO3.
[0030] Furthermore, the spray layer 14 is provided with multiple layers, and the atomization particle size of the upper spray layer 14 is smaller than that of the lower layer. By atomizing the ammonia water, the ammonia water is more fully contacted with the exhaust gas, thereby improving the absorption efficiency.
[0031] Furthermore, a circulating spray layer 16 is provided above and below the demister 17 .
[0032] Furthermore, the demister 1 17 is a flat plate demister, and the demister 2 18 is a tube bundle demister. The demisters are provided to reduce the discharge of atomized ammonia water.
[0033] Furthermore, a flue gas cyclone plate 19 is installed in the straight exhaust chimney 20, and the flue gas cyclone plate 19 retains the ammonia water in the absorption tower, thereby reducing the waste of materials and avoiding the pollution caused by the emission of ammonia.
[0034] Furthermore, a vent valve 5 is installed on the branch of the air inlet pipe equipped with the oxidation blower 4, and the oxidation blower 4 inputs oxygen-containing air into the absorption tower 1 to oxidize NO in the tail gas into NO2.
[0035] Furthermore, the exhaust gas distributor 3 is arranged to have an outlet direction upward, and the exhaust gas distributor 6 is arranged to have an outlet direction downward, so that the exhaust gas and the newly-intaken air can generate convection and fully contact each other.
[0036] The utility model atomizes the ammonia water and fully contacts and reacts with the tail gas, gradually absorbs NO, NO2, SO2 and CO2 in the tail gas, and at the same time collects and processes the ammonia water in a centralized manner after recycling, thereby avoiding ammonia emission and effectively realizing chimney denitrification emission.
[0037] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.
Claims
1. A chimney denitrification emission system, comprising an absorption tower (1), an exhaust gas inlet pipe (2) and a straight exhaust chimney (20), wherein the straight exhaust chimney (20) is located at the top of the absorption tower (1), and is characterized in that: The tail gas inlet pipe (2) is connected to a tail gas distributor (3) installed at the bottom of the absorption tower (1) and above the liquid. A gas distributor (6) is provided above the tail gas distributor (3). The gas distributor (6) is connected to an external oxidation fan (4) through a pipeline. A spray layer (14) is provided above the gas distributor (6). A circulating spray layer (16) and a demister 1 (17) are provided above the spray layer (14). A demister 2 (18) is provided above the demister 1 (17). The spray layer (14) is composed of a plurality of atomizing nozzles. The spray layer (14) is connected to an ammonia storage device through an ammonia feed pipe (12). The ammonia feed pipe (12) is connected to an ammonia storage device through ammonia feed pipe (12). A pressure pump (13) is installed on (12); the circulating spray layer (16) is also composed of a plurality of atomizing nozzles; the circulating spray layer (16) is connected to the bottom of the absorption tower (1) through a circulating pipe (11); a solenoid valve (7), a circulating pump (9) and a solenoid valve (15) are installed on the circulating pipe (11) in sequence from the liquid outlet end to the circulating spray layer connection end; a sewage branch is provided on the circulating pipe (11) between the solenoid valve (7) and the circulating pump (9); a sewage branch is installed on the sewage branch; a liquid replenishment branch is provided on the circulating pipe (11) between the circulating pump (9) and the solenoid valve (15); a water replenishment valve (10) is installed on the liquid replenishment branch.
2. A chimney denitrification emission system according to claim 1, characterized in that: The spray layer (14) is provided with multiple layers.
3. A chimney denitrification emission system according to claim 2, characterized in that: The demister 1 (17) is provided with a circulating spray layer (16) above and below.
4. A chimney denitrification emission system according to claim 3, characterized in that: The demister one (17) is a flat plate demister, and the demister two (18) is a tube bundle demister.
5. A chimney denitrification emission system according to claim 4, characterized in that: A smoke cyclone plate (19) is installed in the straight exhaust chimney (20).
6. A chimney denitration emission system according to claim 5, characterized in that: An air release valve (5) is installed on the branch of the air inlet pipe on which the oxidation fan (4) is installed.
7. The chimney denitration emission system according to claim 1, characterized in that: The exhaust gas distributor (3) is arranged to have an outlet direction facing upwards, and the exhaust gas distributor (6) is arranged to have an outlet direction facing downwards.