Independent heat source grinding station low-nitrogen super-emission system and method

Abstract

The invention relates to a low-nitrogen super-emission system and a low-nitrogen super-emission method for an independent heat source grinding station, and aims to meet increasingly strict environmental protection standards by reducing emission of nitrogen oxides (NOx) generated in a combustion process. According to the system, ultra-low nitrogen oxide emission is achieved through the combination of the low-nitrogen combustor and the flue gas recirculation technology. The low-nitrogen combustor adopts a staged combustion and local oxygen enrichment technology, so that the temperature distribution of flame is effectively controlled, and the generation of NOx is obviously reduced; meanwhile, about 20% of flue gas is recycled and reused through the flue gas recycling technology, the oxygen concentration of a combustion area is effectively reduced, and therefore generation of NOx is further restrained. By means of the process, energy use is optimized, combustion efficiency is improved, and pollution to the environment is remarkably reduced. In addition, the whole system is intelligently controlled, so that the accuracy of operation and the controllability of the process are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of air pollutant treatment, and in particular to a low-nitrogen super-exhaust system and method for an independent heat source grinding station. Background Art

[0002] In industrial grinding stations, hot air furnaces are independent heat source equipment, mainly used to provide high-temperature flue gas required for drying materials. When burning natural gas, coalbed methane or other fuels, traditional hot air furnaces will inevitably produce a variety of air pollutants including nitrogen oxides (NOx), sulfur dioxide (SO2) and particulate matter. Among them, nitrogen oxides (NOx), as a major type of pollutant, are particularly harmful to the environment. It is not only the main cause of acid rain and photochemical smog, but also an important precursor of regional haze, posing a potential serious threat to human health.

[0003] In order to deal with the NOx emission problem, countries and regions have formulated strict emission standards and regulations. For example, China's "Cement Industry Air Pollutant Emission Standard" (GB4915-2013) stipulates the emission limit of NOx in the cement production process, and the relevant environmental protection requirements are becoming more and more stringent. At the same time, the "Opinions on Promoting the Implementation of Ultra-low Emissions in the Cement Industry" jointly issued by the Ministry of Ecology and Environment and other ministries and commissions further emphasized the importance of reducing NOx emissions and proposed more stringent emission standards.

[0004] At present, there are two common technical approaches to reduce NOx emissions: combustion control and flue gas post-treatment. Combustion control technology mainly includes the application of low-nitrogen burners and the optimization and adjustment of the combustion process, and suppresses the generation of NOx by controlling the fuel-air mixing ratio and flame temperature during the combustion process. Flue gas post-treatment technology involves the use of denitrification devices such as selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR) technology to purify the generated NOx.

[0005] For example, the patent number "CN 114060806 A" discloses a method and system for low-nitrogen combustion transformation of a light-fired kiln, which belongs to the field of low-nitrogen combustion technology. The transformation method includes the installation of natural gas pipelines, air mains, and flue gas circulation pipelines; the system includes a light-fired kiln, a burner, a natural gas pipeline, an air main, a flue gas circulation pipeline, an air pipeline, a steam pipeline, a blower, an induced draft fan, a mixer, and a purifier, etc.; this patent is specifically for the "coal to gas" transformation of light-fired kilns, and realizes low-nitrogen combustion, reduces NOx emissions, and ensures stable operation of light-fired kilns, reduces safety hazards, extends service life, and achieves the effect of clean production. It can significantly reduce the emission of nitrogen oxides, which can be reduced by more than 30% compared to general coal-to-gas technology, and the service life of the pipeline can be extended by more than 1 year.

[0006] However, these technologies can reduce NOx emissions to a certain extent, but they often have some limitations. The following problems exist in the low nitrogen emissions of independent heat source grinding stations: 1. SCR technology increases system complexity and cost; 2. The flue gas recirculation method lacks flexible proportional control; 3. The improved burner design cannot take into account both high efficiency and low emissions. Therefore, the development of an innovative technology that is both economical and efficient and can stably and continuously reduce nitrogen oxide emissions has important practical significance and broad application prospects for independent heat source grinding stations and even the entire industrial combustion field. Summary of the invention

[0007] In order to solve the problems of the prior art, the present invention provides a low-nitrogen super-exhaust system and method for an independent heat source grinding station.

[0008] In order to solve the above technical problems, the present invention is implemented through the following technical solutions: In the first aspect, the embodiment of the present application provides a low nitrogen super-exhaust system for an independent heat source grinding station, including: a hot blast furnace main body, a chimney is installed at the top of the hot blast furnace main body for discharging combustion flue gas, and a burner is installed at one end of the hot blast furnace main body for burning combustible gas to heat the inside of the hot blast furnace main body; A circulating smoke pipe, one end of which is fixedly connected to the chimney, one side of the burner is fixedly connected to a mixing chamber, the other end of the circulating smoke pipe is connected through the mixing chamber, the circulating smoke pipe connects the chimney and the mixing chamber through the circulating smoke pipe, and is used to guide the exhaust part of the flue gas to be transported to the mixing chamber for recycling, one side of the mixing chamber is fixedly connected to a combustion-supporting gas pipe, and is used to transport the combustion-supporting gas into the mixing chamber to mix with part of the flue gas, further enter the burner, mix with the gas, and enter the hot blast furnace body to be ignited for use; Control system, the control system consists of a main circuit and a control circuit. The main circuit is used to supply power to electrical equipment, and the control circuit consists of a PLC controller, a real-time monitoring module and an output module; it is used to monitor and control the mixed proportion of flue gas, combustion-supporting gas and combustible gas; A solenoid valve and a fourth gas flow meter are installed inside the gas pipe, and the fourth gas flow meter is arranged close to one side of the burner; A smoke separation device is installed in the middle of the circulating smoke duct, and the smoke separation device is fixedly connected to the hot blast stove body; a filtering mechanism is installed inside the smoke separation device, a storage chamber is provided on one side of the interior of the smoke separation device, and a third variable-speed fan is installed on the other side of the interior of the smoke separation device, an input hole is provided at one end of the smoke separation device, and an output pipe is provided at the other end of the smoke separation device, the input hole and the output pipe are respectively connected with the circulating smoke duct, the input hole, the storage chamber, the filtering mechanism, the third variable-speed fan and the output pipe are connected for conveying smoke, and the interior of the output pipe is provided with an input hole, and the output pipe is provided with an output pipe. A third gas flow meter is installed to detect the internal gas flow rate; the filtering mechanism consists of a motor, a rotating disk, a limit slide and a filter cover; the motor is fixedly connected to the smoke separation device, the output end of the motor is fixedly connected to the rotating disk, a limit slide is arranged on the outer side of the limit slide, the number of the limit slides is set to multiple, and the multiple limit slides are equidistantly distributed in a circular ring shape inside the rotating disk, the inner wall of the limit slide is limitedly slidably connected to the filter cover, the filter cover is used to intercept solid particles in the smoke and store them inside the storage chamber; a cover is installed on the top of the smoke separation device.

[0009] In the embodiment of the present application, the flue gas is discharged from the chimney at the top of the hot blast furnace body, and part of the flue gas is guided to the mixing chamber through the circulating smoke duct, mixed with the combustion-supporting gas and then enters the burner again for combustion, thereby reducing the amount of fresh air inhaled and the oxygen concentration, thereby reducing the generation of nitrogen oxides and reducing pollution to the environment.

[0010] In some possible implementations of the first aspect, a first variable speed fan and a first gas flow meter are installed inside one end of the circulating smoke pipe, and the first gas flow meter is arranged close to one side of the mixing chamber. A second variable speed fan and a second gas flow meter are installed inside the combustion-supporting gas pipe, and the second gas flow meter is arranged close to one side of the mixing chamber.

[0011] The first variable speed fan and the first gas flow meter in the circulating smoke duct, and the second variable speed fan and the second gas flow meter in the combustion-supporting gas duct, accurately control the flow rate and mixing ratio of the smoke and combustion-supporting gas to ensure maximum combustion efficiency while reducing the generation of nitrogen oxides.

[0012] The flue gas separation device filters the recirculated flue gas to remove solid particles. The filter mechanism consists of a rotating disk driven by a motor and filter covers in multiple limit slides, which are used to intercept solid particles in the flue gas and store them inside the storage chamber. This ensures that only clean flue gas re-enters the system for recycling, reducing the emission of pollutants; the third gas flow meter monitors the gas flow at the output pipe end. When the flow is far below the preset value, the PLC controller determines that the filter cover is blocked and drives the rotating disk to rotate through the motor, so that a new filter cover is replaced to continue the filtering process. The control system is also equipped with automatic diagnosis and fault handling procedures to respond to abnormal situations in real time to ensure the safe and stable operation of the system.

[0013] In some possible implementations of the first aspect, the input end of the PLC controller is electrically connected to the real-time monitoring module, and the output end of the PLC controller is electrically connected to the output module; the output module includes a first variable-speed fan, a second variable-speed fan, a third variable-speed fan, a solenoid valve and a motor; the real-time monitoring module includes a first gas flow meter, a second gas flow meter, a third gas flow meter and a fourth gas flow meter. A control cabinet is installed on one side of the hot air furnace body, and the PLC controller is installed inside the control cabinet.

[0014] The control system includes a PLC controller, a real-time monitoring module and an output module, which are used to monitor and control the mixing ratio of flue gas, combustion-supporting gas and combustible gas. Real-time monitoring of key parameters such as gas flow, etc., automatically adjusts the operating status of each fan and valve to achieve low nitrogen emissions.

[0015] In a second aspect, the embodiment of the present application provides a low nitrogen super-exhaust method for an independent heat source grinding station, and the specific steps include: Step 1: Flue gas recycling and control The circulating smoke pipe is used to guide part of the smoke from the chimney to the mixing chamber. After mixing with the combustion-supporting gas in the mixing chamber, the smoke enters the burner again for combustion. This can reduce the intake of fresh air, reduce the oxygen concentration, and thus reduce the generation of nitrogen oxides. Step 2: Gas flow and ratio control Through the installed first variable speed fan, second variable speed fan, third variable speed fan and corresponding gas flow meter, the flow rate and mixing ratio of flue gas, combustion-supporting gas and combustible gas are accurately controlled to ensure the maximum combustion efficiency and reduce the generation of nitrogen oxides; Step 3: Flue gas cleaning The flue gas separation device filters the recirculated flue gas to remove solid particles. The filtered flue gas re-enters the system for recycling, reducing pollutant emissions; Step 4: Real-time monitoring and adjustment The key parameters of the combustion process are monitored in real time using the PLC controller and real-time monitoring module, and the operating status of each fan and valve is automatically adjusted through the output module to achieve low nitrogen emissions; Step 5: Maintenance and Cleaning The third gas flow meter monitors the gas flow at the output pipe end in real time. When the flow is far lower than the preset value, the PLC controller determines that the filter cover is blocked. At this time, the control motor is controlled to rotate the output end by ninety degrees and replace it with a new filter cover to continue filtering.

[0016] The PLC controller is also equipped with automatic diagnosis and fault handling procedures to respond to abnormal situations in real time and ensure the safe and stable operation of the system.

[0017] The key parameters monitored by the real-time monitoring module include flue gas temperature, oxygen content and nitrogen oxide concentration, so as to more accurately control the combustion process and optimize the low nitrogen emission effect.

[0018] Since the operating method provided in the embodiment of the present application is the method flow of the low-nitrogen super-exhaust system of the independent heat source grinding station as described in any of the above technical solutions, the two can solve the same technical problems and achieve the same technical effects.

[0019] The beneficial effects of the present invention are: 1. Ultra-low nitrogen oxide emissions of independent heat source grinding stations are achieved by combining low-nitrogen burners with flue gas recirculation technology. The low-nitrogen burner adopts staged combustion and local oxygen enrichment technology to effectively control the temperature distribution of the flame and reduce the generation of NOx. At the same time, about 20% of the flue gas is recovered and reused through flue gas recirculation technology, which reduces the oxygen concentration and further inhibits the generation of NOx. This process not only optimizes energy use and improves combustion efficiency, but also significantly reduces pollution to the environment. In addition, the entire system ensures the accuracy of operation and controllability of the process through intelligent control; 2. By adopting low-nitrogen burners and flue gas recirculation technology, NOx emissions can be reduced to below 30mg / m^3, which is far better than the current environmental protection standards and effectively reduces pollution to the atmospheric environment. Staged combustion and local oxygen-enriched combustion technology help reduce the emission of other pollutants such as sulfur dioxide and particulate matter, and further improve air quality; 3. The present invention does not require large-scale changes to the existing hot blast furnace, but only requires adjustment and optimization of the heat source and flue gas circulation system, thus reducing the implementation cost. Flue gas recirculation technology reduces energy waste and improves overall combustion efficiency by recycling flue gas, thereby saving fuel consumption and maintenance costs; 4. Reduce the emission of harmful gases such as nitrogen oxides, reduce the incidence of air pollution events such as smog, and help improve people's respiratory health. The use of advanced environmental protection technology can enhance the green image of enterprises, enhance the trust of consumers and society, and is conducive to the long-term development of enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall system of the first embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of the overall system of the second embodiment of the present invention.

[0022] Figure 3 It is a schematic diagram of a multiple gas mixing structure according to the first embodiment of the present invention.

[0023] Figure 4 It is a schematic diagram of a multi-gas mixing structure of the second embodiment of the present invention.

[0024] Figure 5 It is a schematic diagram of the internal structure of the smoke separation device of the second embodiment of the present invention.

[0025] Figure 6 It is a schematic diagram of the motor transmission structure of the present invention.

[0026] Figure 7 It is a schematic diagram of the control connection of the PLC controller of the present invention.

[0027] Figure 8 It is a schematic diagram of the internal structure of the output module of the present invention.

[0028] Fig. 9 It is a schematic diagram of the internal structure of the real-time monitoring module of the present invention.

[0029] Figures 1 to 9 Middle: 1. Hot air furnace body; 11. Control cabinet; 2. Burner; 21. Gas pipe; 211. Solenoid valve; 212. Fourth gas flow meter; 3. Chimney; 4. circulating smoke pipe; 41. first variable speed fan; 42. first gas flow meter; 5. Mixing chamber; 51. Combustion-supporting gas pipe; 511. Second variable-speed fan; 512. Second gas flow meter; 6. Smoke separation device; 61. Filter mechanism; 611. Motor; 612. Rotating disk; 613. Limiting slide; 614. Filter cover; 62. Third variable speed fan; 63. Storage chamber; 64. Input hole; 65. Cover plate; 66. Output pipe; 67. Third gas flow meter; 7. PLC controller; 71. Real-time monitoring module; 72. Output module. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that, in the description of the present invention, terms such as "center", "upper", "lower", "horizontal", "inner", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0032] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Example 1: Please refer to Figure 1 , Figure 3 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, the embodiment of the present application provides a low nitrogen super-exhaust system for an independent heat source grinding station, including: a hot blast furnace body 1, a chimney 3 is installed on the top of the hot blast furnace body 1 for discharging combustion flue gas, and a burner 2 is installed at one end of the hot blast furnace body 1 for burning combustible gas to heat the inside of the hot blast furnace body 1; A circulating smoke pipe 4, one end of which is fixedly connected to the chimney 3, a mixing chamber 5 is fixedly connected to one side of the burner 2, and the other end of the circulating smoke pipe 4 is connected through the mixing chamber 5. The circulating smoke pipe 4 connects the chimney 3 with the mixing chamber 5, and is used to guide the exhaust part of the smoke to be transported to the mixing chamber 5 through the circulating smoke pipe 4 for recycling. A combustion-supporting gas pipe 51 is fixedly connected to one side of the mixing chamber 5, and is used to transport the combustion-supporting gas into the mixing chamber 5 to mix with part of the smoke, and further enter the burner 2 to mix with the fuel gas and enter the hot blast stove body 1 to be ignited for use; The control system consists of a main circuit and a control circuit. The main circuit is used to supply power to electrical equipment. The control circuit consists of a PLC controller 7, a real-time monitoring module 71 and an output module 72. The control circuit is used to monitor and control the mixed proportion of flue gas, combustion-supporting gas and combustible gas.

[0034] The input end of the PLC controller 7 is electrically connected to the real-time monitoring module 71, and the output end of the PLC controller 7 is electrically connected to the output module 72; the output module 72 includes the first variable speed fan 41, the second variable speed fan 511, the third variable speed fan 62, the solenoid valve 211 and the motor 611; the real-time monitoring module 72 includes the first gas flow meter 42, the second gas flow meter 512, the third gas flow meter 67 and the fourth gas flow meter 212. A control cabinet 11 is installed on one side of the hot air furnace body 1, and the PLC controller 7 is installed inside the control cabinet 11.

[0035] In this way, the hot blast stove body 1 is the core component, and the material is heated by the high-temperature flame generated by the burner 2. The burner 2 is located at one end of the hot blast stove body 1, and is responsible for igniting the combustible gas and generating a high-temperature flame. At the same time, the chimney 3 is installed at the top of the hot blast stove body to discharge the smoke generated by the combustion; In order to reduce the emission of nitrogen oxides, the system adopts the design of a circulating smoke pipe 4. One end of the circulating smoke pipe 4 is fixedly connected to the chimney 3, and the other end is connected to the mixing chamber 5. In this way, part of the flue gas can be guided to the mixing chamber 5 through the circulating smoke pipe 4 for recycling. In the mixing chamber 5, the combustion-supporting gas pipe 51 transports the combustion-supporting gas in and mixes with part of the flue gas. This mixed gas further enters the burner to mix with the fuel gas, and finally enters the hot blast stove body 1 to be ignited and used.

[0036] The control system is the brain of the entire system, consisting of a main circuit and a control circuit. The main circuit is responsible for supplying power to electrical equipment, while the control circuit consists of a PLC controller, a real-time monitoring module, and an output module. The control system can monitor the mixed ratio of flue gas, combustion-supporting gas, and combustible gas in real time, and make adjustments as needed to ensure stable operation of the system and low nitrogen emissions.

[0037] A first variable speed fan 41 and a first gas flow meter 42 are installed inside one end of the circulating smoke pipe 4, and the first gas flow meter 42 is arranged near the mixing chamber 5. A second variable speed fan 511 and a second gas flow meter 512 are installed inside the combustion-supporting gas pipe 51, and the second gas flow meter 512 is arranged near the mixing chamber 5. A solenoid valve 211 and a fourth gas flow meter 212 are installed inside the gas pipe 21, and the fourth gas flow meter 212 is arranged near the burner 2.

[0038] In the first embodiment, the core of the low nitrogen super-exhaust system of the independent heat source grinding station is the hot blast furnace body 1. The combustible gas is ignited by the burner 2 to generate a high-temperature flame to heat the material. In order to reduce the emission of nitrogen oxides (NOx), the system adopts the design of a circulating smoke pipe 4 to reintroduce part of the smoke into the mixing chamber 5 for recycling. This not only improves the thermal efficiency, but also reduces the emission of harmful gases.

[0039] The control system consists of a main circuit and a control circuit, wherein the PLC controller 7 is responsible for monitoring and adjusting the mixing ratio of flue gas, combustion-supporting gas and combustible gas to maintain the stable operation of the system and achieve low nitrogen emissions. Through the real-time monitoring module 71 and the output module 72, the flow rate and ratio of each component can be accurately controlled to ensure the optimization of the combustion process.

[0040] Example 2: Please refer to the attached Figure 2 , Figure 4 , Figure 5 and Figure 6 As shown, a flue gas separation device 6 is installed in the middle of the circulating smoke pipe 4, and the flue gas separation device 6 is fixedly connected to the hot blast stove body 1; a filtering mechanism 61 is installed inside the flue gas separation device 6, a storage chamber 63 is provided on one side of the interior of the flue gas separation device 6, and a third variable speed fan 62 is installed on the other side of the interior of the flue gas separation device 6, an input hole 64 is provided at one end of the flue gas separation device 6, and an output pipe 66 is provided at the other end of the flue gas separation device 6, and the input hole 64 and the output pipe 66 are respectively connected with the circulating smoke pipe 4, and the input hole 64, the storage chamber 63, the filtering mechanism 61, the third variable speed fan 62 and the output pipe 66 are connected for conveying smoke, and a third gas flowmeter is installed inside the output pipe 66. The device 67 is used to detect the internal gas flow rate; the filtering mechanism 61 is composed of a motor 611, a rotating disk 612, a limiting slide 613 and a filter cover 614. The motor 611 is fixedly connected to the smoke separation device 6, and the output end of the motor 611 is fixedly connected to the rotating disk 612. The outer side of the limiting slide 613 is provided with a limiting slide 613. The number of the limiting slides 613 is set to multiple, and the multiple limiting slides 613 are equidistantly distributed in a circular ring shape inside the rotating disk 612. The inner wall of the limiting slide 613 is slidingly connected with a filter cover 614. The filter cover 614 is used to intercept solid particles in the smoke and store them inside the storage chamber 63; a cover plate 65 is installed at the top of the smoke separation device 6.

[0041] Compared with the first embodiment, this embodiment further enhances the environmental performance of the system by adding a flue gas separation device 6 to the circulating smoke pipe 4. A filter mechanism 61 is provided inside the flue gas separation device 6, including a motor 611, a rotating disk 612, a limiting slide 613 and a filter cover 614. These components work together to effectively intercept solid particles in the flue gas and store them in the storage chamber 63. This arrangement helps to reduce the solid waste generated during combustion, reduce the emission of particulate matter in the exhaust flue gas, reduce the impact on the secondary re-combustion of the flue gas, and at the same time reduce the accumulation or blockage of soot when the burner 2 is burning, thereby ensuring the combustion effect.

[0042] The smoke separation device 6 also includes a motor 611 and four filter covers 614. When the filter covers 614 are attached with particulate matter and hinder the flow of smoke, the third gas flow meter 67 is triggered and transmits the trigger signal to the PLC controller, thereby controlling the operation of the motor 611, driving the filter cover to rotate 90 degrees, and further driving a new filter cover 614 to continue filtering.

[0043] The flue gas separation device 6 also includes a third variable speed fan 62 and a third gas flow meter 67, which are used to adjust the flow rate of the treated flue gas to ensure the stability and controllability of the flue gas flow. The cover plate 65 may be added to protect the internal machinery from environmental factors and facilitate maintenance and repair.

[0044] The low nitrogen super-exhaust method of the independent heat source grinding station includes the following specific steps: Step 1: Flue gas recycling and control A circulating smoke pipe 4 is used to guide part of the flue gas from the chimney 3 to the mixing chamber 5. After being mixed with the combustion-supporting gas in the mixing chamber, the flue gas enters the burner 2 again for combustion. By recycling part of the flue gas, the demand for fresh air is reduced, the oxygen concentration is lowered, and thus the generation of NOx is reduced; Step 2: Gas flow and ratio control The first variable speed fan 41, the second variable speed fan 511, the third variable speed fan 62 and the corresponding gas flow meters are installed to accurately control the flow rate and mixing ratio of the flue gas, the combustion-supporting gas and the combustible gas to ensure the maximum combustion efficiency and reduce the generation of nitrogen oxides; Step 3: Flue gas cleaning The flue gas separation device 6 filters the recirculated flue gas to remove solid particles. The filtered flue gas re-enters the system for recycling, reducing pollutant emissions; Step 4: Real-time monitoring and adjustment The key parameters of the combustion process are monitored in real time by using the PLC controller 7 and the real-time monitoring module 71, and the operating status of each fan and valve is automatically adjusted through the output module 72 to achieve low nitrogen emissions; Step 5: Maintenance and Cleaning The third gas flow meter 67 monitors the gas flow at the output pipe 66 in real time. When the flow is much lower than the preset value 32, the PLC controller 7 determines that the filter cover 614 is blocked. At this time, the control motor 611 controls the output end to rotate 90 degrees and replace it with a new filter cover 614 for continued filtering. The PLC controller 7 is also equipped with an automatic diagnosis and fault handling program for real-time response to abnormal situations to ensure safe and stable operation of the system.

[0045] The key parameters monitored by the real-time monitoring module 71 include flue gas temperature, oxygen content and nitrogen oxide concentration, so as to more accurately control the combustion process and optimize the low nitrogen emission effect.

[0046] In summary: The nitrogen oxide (NOx) emission problem of independent heat source grinding stations has become a key concern in the field of environmental protection. With the increasingly stringent national and local policies, traditional combustion technology has been difficult to meet the new emission standards. To meet this challenge, this paper proposes an innovative solution combining low-nitrogen burners and flue gas recirculation technology (FGR).

[0047] First, the low-nitrogen burner achieves staged combustion and local oxygen-enriched combustion by precisely controlling the ratio of natural gas, combustion air and circulating flue gas, thereby effectively reducing the generation of NOx. This burner is operated by an independent control cabinet to ensure the stability and continuity of the combustion process.

[0048] Secondly, the flue gas recirculation technology recycles part of the flue gas (about 20%) and mixes it with the combustion air before sending it back into the furnace for combustion. This practice not only changes the temperature distribution of the flame and reduces the amount of NOx generated, but also reduces NOx emissions to below 30mg / m^3, which is far below the current standard.

[0049] The significant advantage of the present invention is that it only requires modification and adjustment of the heat source and the flue gas circulation system, without large-scale modification of the hot air furnace itself, which greatly reduces the modification cost and implementation difficulty. In addition, by effectively reducing the nitrogen oxide content in the flue gas of the drying equipment, the present invention not only helps to protect the environment and reduce air pollution, but also helps to protect human health.

[0050] In general, the research and development and application of this independent heat source grinding station stable continuous nitrogen oxide concentration ultra-low emission technology demonstrates the possibility and potential of achieving ultra-low emissions in the field of industrial combustion. It not only meets the country's strategic needs for environmental protection and sustainable development, but also provides a feasible path for related companies to meet new environmental standards. With the continuous optimization of technology and the expansion of its application scope, it is expected to play a more important role in future industrial production.

[0051] The present invention and its embodiments are described above, and such description is not restrictive. What is shown in the full text is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. Low nitrogen super-exhaust system of independent heat source grinding station, characterized by: include: A hot blast stove body (1), wherein a chimney (3) is installed at the top of the hot blast stove body (1) for discharging combustion flue gas, and a burner (2) is installed at one end of the hot blast stove body (1) for burning combustible gas to heat the interior of the hot blast stove body (1); A circulating smoke pipe (4), one end of the circulating smoke pipe (4) is fixedly connected to the chimney (3), one side of the burner (2) is fixedly connected to a mixing chamber (5), the other end of the circulating smoke pipe (4) is connected in a through-connection with the mixing chamber (5), the circulating smoke pipe (4) connects the chimney (3) and the mixing chamber (5) in a through-connection manner, and is used to guide a portion of the exhaust smoke to be transported to the mixing chamber (5) through the circulating smoke pipe (4) for recycling, and one side of the mixing chamber (5) is fixedly connected to a combustion-supporting gas pipe (51) for transporting the combustion-supporting gas into the mixing chamber (5) to mix with a portion of the smoke, and further enter the burner (2) to mix with the fuel gas and enter the hot blast furnace body (1) to be ignited for use; A control system, the control system is composed of a main circuit and a control circuit, the main circuit is used to supply power to electrical equipment, and the control circuit is composed of a PLC controller (7), a real-time monitoring module (71) and an output module (72); and is used to monitor and control the mixed proportion of flue gas, combustion-supporting gas and combustible gas; A solenoid valve (211) and a fourth gas flow meter (212) are installed inside the gas pipe (21), and the fourth gas flow meter (212) is arranged close to one side of the burner (2); A smoke separation device (6) is installed at the middle of the circulating smoke pipe (4), and the smoke separation device (6) is fixedly connected to the hot blast stove body (1); A filter mechanism (61) is installed inside the smoke separation device (6), a storage chamber (63) is provided on one side of the smoke separation device (6), a third variable speed fan (62) is installed on the other side of the smoke separation device (6), an input hole (64) is provided at one end of the smoke separation device (6), an output pipe (66) is provided at the other end of the smoke separation device (6), the input hole (64) and the output pipe (66) are respectively connected to the circulating smoke pipe (4), the input hole (64), the storage chamber (63), the filter mechanism (61), the third variable speed fan (62) and the output pipe (66) are connected to convey smoke, and a third gas flow meter (67) is installed inside the output pipe (66) for detecting the internal gas flow rate; The filtering mechanism (61) is composed of a motor (611), a rotating disk (612), a limiting slide groove (613) and a filter cover (614); the motor (611) is fixedly connected to the smoke separation device (6); the output end of the motor (611) is fixedly connected to the rotating disk (612); a limiting slide groove (613) is arranged outside the limiting slide groove (613); the number of the limiting slide grooves (613) is set to be multiple; the multiple limiting slide grooves (613) are equidistantly distributed in a circular ring shape inside the rotating disk (612); the inner wall of the limiting slide groove (613) is limitedly slidably connected to the filter cover (614); the filter cover (614) is used to intercept solid particles in the smoke and store them inside the storage chamber (63); A cover plate (65) is installed on the top of the smoke separation device (6).

2. The low nitrogen super-exhaust system for an independent heat source grinding station according to claim 1 is characterized in that: A first variable speed fan (41) and a first gas flow meter (42) are installed inside one end of the circulating smoke pipe (4), and the first gas flow meter (42) is arranged close to one side of the mixing chamber (5).

3. The low nitrogen super-exhaust system for an independent heat source grinding station according to claim 1 is characterized in that: A second variable-speed fan (511) and a second gas flow meter (512) are installed inside the combustion-supporting gas pipe (51), and the second gas flow meter (512) is arranged close to one side of the mixing chamber (5).

4. The low nitrogen super-exhaust system for an independent heat source grinding station according to claim 1 is characterized in that: The input end of the PLC controller (7) is electrically connected to the real-time monitoring module (71), and the output end of the PLC controller (7) is electrically connected to the output module (72); The output module (72) includes a first variable speed fan (41), a second variable speed fan (511), a third variable speed fan (62), a solenoid valve (211) and a motor (611); The real-time monitoring module (71) comprises a first gas flow meter (42), a second gas flow meter (512), a third gas flow meter (67) and a fourth gas flow meter (212).

5. The low nitrogen super-exhaust system for an independent heat source grinding station according to claim 1 is characterized in that: A control cabinet (11) is installed on one side of the hot air stove body (1), and the PLC controller (7) is installed inside the control cabinet (11).

6. Low nitrogen super-exhaust method for independent heat source grinding station, characterized in that: The specific steps include: Step 1: Flue gas recycling and control A circulating smoke pipe (4) is used to guide part of the smoke from the chimney (3) to the mixing chamber (5), where the smoke is mixed with the combustion-supporting gas and then enters the burner (2) again for combustion, thereby reducing the amount of fresh air inhaled and the oxygen concentration, thereby reducing the generation of nitrogen oxides; Step 2: Gas flow and ratio control By installing a first variable speed fan (41), a second variable speed fan (511), a third variable speed fan (62) and corresponding gas flow meters, the flow rates and mixing ratios of flue gas, combustion-supporting gas and combustible gas are precisely controlled to ensure maximum combustion efficiency while reducing the generation of nitrogen oxides; Step 3: Flue gas cleaning The flue gas separation device (6) filters the recirculated flue gas to remove solid particles therein, and the filtered flue gas re-enters the system for recycling, thereby reducing pollutant emissions; Step 4: Real-time monitoring and adjustment The PLC controller (7) and the real-time monitoring module (71) are used to monitor key parameters in the combustion process in real time, and the operating status of each fan and valve is automatically adjusted through the output module (72) to achieve low nitrogen emissions; Step 5: Maintenance and Cleaning The third gas flow meter (67) monitors the gas flow at the end of the output pipe (66) in real time. When the flow is far below the preset value (32), the PLC controller (7) determines that the filter cover (614) is blocked. At this time, the control motor (611) is controlled to rotate the output end by ninety degrees and replace it with a new filter cover (614) to continue filtering.

7. The low nitrogen super-exhaust method for an independent heat source grinding station according to claim 6, characterized in that: The PLC controller (7) is also equipped with an automatic diagnosis and fault handling program for responding to abnormal situations in real time to ensure safe and stable operation of the system.

8. The low nitrogen super-exhaust method for an independent heat source grinding station according to claim 6, characterized in that: The key parameters monitored by the real-time monitoring module (71) include flue gas temperature, oxygen content and nitrogen oxide concentration, so as to more accurately control the combustion process and optimize the low nitrogen emission effect.

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