System for reducing nitrogen oxide of boiler
By introducing the boiler exhaust gas into the flue gas return pipe of the lime kiln and mixing it with the gas in the lime kiln, the exhaust gas is recycled and diluted, which solves the problem of excessive nitrogen oxides in the gas-fired boiler of the calcium carbide furnace exhaust gas, and achieves a dual improvement in environmental protection and production efficiency.
Patent Information
- Application Number
- CN202422547252.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-22
AI Technical Summary
The nitrogen oxide content in the gas-fired boiler of calcium carbide furnace exhaust exceeds the standard, affecting environmental protection requirements and production capacity.
The boiler exhaust gas is introduced into the flue gas return pipe of the lime kiln and mixed into the driving air and cooling air system of the lime kiln by a circulating fan to achieve exhaust gas recirculation and dilution, reduce oxygen concentration and inhibit the generation of nitrogen oxides.
Through exhaust gas recirculation and dilution, the generation of nitrogen oxides is significantly reduced, meeting environmental protection requirements and improving production efficiency.
Smart Images
Figure CN223345418U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of nitrogen oxide purification, and in particular relates to a system for reducing nitrogen oxides in boilers. Background Art
[0002] In the calcium carbide industry, a calcium carbide furnace tail gas gas boiler is a unique energy recovery and reuse device. This device uses the tail gas generated during the calcium carbide furnace production process as fuel, generating heat through combustion, which is then converted into electricity or used for other industrial purposes. This treatment method not only avoids the environmental pollution caused by direct tail gas emissions, but also creates economic benefits and maximizes resource utilization.
[0003] However, due to the complex composition of the exhaust gas from the calcium carbide furnace, especially the unstable content of carbon monoxide, the nitrogen oxide content produced during the combustion process exceeds the standard, which does not meet environmental protection requirements and limits the production capacity of the boiler. Utility Model Content
[0004] In response to the problems existing in the existing technology, the utility model provides a system for reducing boiler nitrogen oxides, which solves the problem of excessive nitrogen oxides in the production process of calcium carbide furnace tail gas gas boilers, and provides strong technical support and guarantee for the green development of the calcium carbide industry and the effective use of resources.
[0005] The technical solutions used in this utility model are as follows:
[0006] A system for reducing boiler nitrogen oxides includes a gas boiler, a lime kiln, a dust collector, a multi-tube cooler, a variable frequency induced draft fan, a circulating fan and an air suspension fan.
[0007] The lime kiln includes a chimney, a driving air system and a lime cooling air system.
[0008] The chimney outlet is connected to the input end of the dust collector through a flue gas return pipe, the output end of the dust collector is connected to the input end of the multi-tube cooler through a pipeline, the output end of the multi-tube cooler is connected to the circulation fan, the circulation fan outlet is connected to a branch pipe, the branch pipe's first fork is connected to the air suspension fan, the air suspension fan is connected to the driving air system through a pipeline, and the branch pipe's second fork is connected to the lime cooling air system.
[0009] The gas boiler is connected to the inlet of the variable frequency induced draft fan through a pipeline, and the outlet of the variable frequency induced draft fan is connected to the flue gas return pipe through a pipeline.
[0010] Furthermore, it also includes a burner, which is connected to the gas boiler.
[0011] Furthermore, an electric regulating valve and a manual damper are sequentially provided on the pipeline connecting the gas boiler and the variable frequency induced draft fan.
[0012] Furthermore, a manual plug-in valve is provided on the multi-tube cooler.
[0013] Furthermore, the lime cooling air system includes a lime cooling air pipe, and the second fork of the branch pipe is connected to the lime cooling air pipe.
[0014] The beneficial effects of the utility model are:
[0015] 1. In the utility model, the tail gas generated by the gas boiler is introduced into the flue gas return pipe of the lime kiln, and the circulating fan is used to lead the mixed tail gas back to the driving air system and lime cooling air system of the lime kiln, thereby realizing the recycling and reuse of the tail gas, reducing the direct emission of the tail gas and the pollution to the environment.
[0016] 2. In this utility model, boiler exhaust gas is introduced into the lime kiln's flue gas return duct. Since the boiler exhaust gas has an extremely low oxygen content, when it mixes with the gases in the lime kiln, it can reduce the overall oxygen concentration, thereby suppressing the formation of nitrogen oxides. Furthermore, the lime kiln is much larger than a gas-fired boiler, so the exhaust gas is more significantly diluted within the lime kiln, further reducing the formation of nitrogen oxides. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a structural diagram of a system for reducing boiler nitrogen oxides provided by the utility model.
[0018] In the accompanying drawings, the components represented by the reference numerals are as follows:
[0019] 1. Gas boiler; 2. Chimney; 3. Variable frequency induced draft fan; 4. Dust collector; 5. Multi-tube cooler; 6. Circulating fan; 7. Air suspension fan; 8. Drive air system; 9. Lime cooling air system; 10. Manual gate valve; 11. Burner; 12. Electric regulating valve; 13. Manual damper; 14. Lime cooling air pipe; 15. Flue gas return pipe; 16. Branch pipe; 161. Fork in the road one; 162. Fork in the road two. DETAILED DESCRIPTION
[0020] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention; it is obvious that the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.
[0021] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," and "connected" should be understood in a broad sense; for example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0022] like Figure 1 As shown, this embodiment provides a system for reducing boiler nitrogen oxides, comprising a gas boiler (1), a lime kiln, a dust collector (4), a multi-tube cooler (5), a variable frequency induced draft fan (3), a circulating fan (6), an air suspension fan (7) and a burner (11), wherein the lime kiln comprises a chimney (2), a driving air system (8) and a lime cooling air system (9), the lime cooling air system (9) comprises a lime cooling air pipe (14), the chimney (2) outlet is connected to the input end of the dust collector (4) through a flue gas return pipe (15), and the output end of the dust collector (4) is connected to the multi-tube cooler through a pipeline. The input end of the multi-tube cooler (5) is connected, a manual plug valve (10) is provided on the multi-tube cooler (5), the output end of the multi-tube cooler (5) is connected to the circulation fan (6), the circulation fan (6) is connected to one end of the branch pipe (16), the first fork (161) of the branch pipe (16) is connected to the air suspension fan (7), the air suspension fan (7) is connected to the driving air system (8) through a pipeline, the second fork (162) of the branch pipe (16) is connected to the lime cooling air pipe (14), and then connected to the lime cooling air system (9), so that the tail gas is introduced into the lime cooling air system (9).
[0023] The burner (11) is connected to the gas boiler (1), the gas boiler (1) is connected to the inlet of the variable frequency induced draft fan (3) through a pipeline, the outlet of the variable frequency induced draft fan (3) is connected to the flue gas return pipe (15) through a pipeline, and an electric regulating valve (12) and a manual damper (13) are sequentially arranged on the pipeline connecting the gas boiler (1) and the variable frequency induced draft fan (3).
[0024] The gas boiler (1) generates exhaust gas containing nitrogen oxides. Under the action of the variable frequency induced draft fan (3), it is drawn through a pipeline into the flue gas return pipe (15) and mixed with the boiler exhaust gas. At the same time, the electric control valve (12) cooperates with the variable frequency induced draft fan (3) to adjust the flow rate of the exhaust gas, maintaining the pressure in the furnace stable at 2-4Pa. The manual damper (13) serves as a backup adjustment method to manually adjust the flow rate of the exhaust gas, further ensuring the safe operation of the boiler and improving the boiler's thermal efficiency. The oxygen content in the boiler exhaust gas is extremely low. When it mixes with the gas in the lime kiln, it can reduce the overall oxygen concentration of the mixed exhaust gas, thereby reducing the generation of nitrogen oxides.
[0025] The mixed exhaust gas, under the action of the circulating fan (6), flows into the dust collector (4) through the flue gas return pipe (15) for filtration to remove particulate matter in the exhaust gas and prevent the particulate matter from polluting subsequent equipment and the working environment. The filtered exhaust gas is cooled by the multi-tube cooler (5) to make it suitable for subsequent processing and protect subsequent equipment from damage caused by high-temperature exhaust gas. The manual gate valve (10) provided in the multi-tube cooler (5) is used to control the flow rate of the exhaust gas, ensuring that the exhaust gas can enter the circulating fan (6) as needed, and finally sent to the driving air system (8) and lime cooling air system (9) of the lime kiln through the branch pipe (16).
[0026] The driving air system (8) is mainly used to provide the necessary air flow for the lime kiln to support the combustion and decomposition process in the kiln. The lime cooling air system (9) is mainly used to cool the calcined lime. By introducing cooling air, the temperature of the high-temperature lime is quickly reduced, so that it reaches suitable subsequent processing conditions. The filtered cooling exhaust gas is respectively introduced to the driving air system (8) and the lime cooling air system (9), which can achieve the recycling and reuse of the exhaust gas, reducing the direct emission of exhaust gas and pollution to the environment. In addition, the volume of the lime kiln is much larger than that of the gas boiler (1). Therefore, the dilution effect of the mixed exhaust gas in the lime kiln is more significant, further reducing the generation content of nitrogen oxides, not only meeting production requirements, but also meeting environmental protection requirements.
[0027] The above describes an embodiment of the present invention in detail. However, the content is only a preferred embodiment of the present invention and should not be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.
Claims
1. A system for reducing boiler nitrogen oxides, characterized in that: It includes a gas boiler (1), a lime kiln, a dust collector (4), a multi-tube cooler (5), a variable frequency induced draft fan (3), a circulating fan (6) and an air suspension fan (7). The lime kiln comprises a chimney (2), a driving air system (8) and a lime cooling air system (9), The chimney (2) outlet is connected to the input end of the dust collector (4) through a flue gas return pipe (15), the output end of the dust collector (4) is connected to the input end of the multi-tube cooler (5) through a pipeline, the output end of the multi-tube cooler (5) is connected to the circulation fan (6), the circulation fan (6) outlet is connected to a branch pipe (16), a fork (161) of the branch pipe (16) is connected to the air suspension fan (7), the air suspension fan (7) is connected to the driving air system (8) through a pipeline, and a fork (162) of the branch pipe (16) is connected to the lime cooling air system (9). The gas boiler (1) is connected to the inlet of the variable frequency induced draft fan (3) through a pipeline, and the outlet of the variable frequency induced draft fan (3) is connected to the flue gas return pipe (15) through a pipeline.
2. The system for reducing boiler nitrogen oxides according to claim 1, characterized in that: It also includes a burner (11), which is connected to the gas boiler (1).
3. The system for reducing boiler nitrogen oxides according to claim 1, characterized in that: An electric regulating valve (12) and a manual damper (13) are sequentially provided on the pipeline connecting the gas boiler (1) and the variable frequency induced draft fan (3).
4. The system for reducing boiler nitrogen oxides according to claim 1, characterized in that: The multi-tube cooler (5) is provided with a manual gate valve (10).
5. The system for reducing boiler nitrogen oxides according to claim 1, characterized in that: The lime cooling air system (9) comprises a lime cooling air pipe (14), and the second fork (162) of the branch pipe (16) is connected to the lime cooling air pipe (14).