Low-nitrogen ultra-low-emission system and method for independent heat source grinding station

Abstract

The present invention relates to a low-nitrogen ultra-low emission system and method for an independent heat source grinding station, aiming to reduce the emissions of nitrogen oxides (NOx) generated during the combustion process to meet increasingly stringent environmental protection standards. The system achieves ultra-low nitrogen oxide emissions through the combination of a low-nitrogen burner and flue gas recirculation technology. The low-nitrogen burner adopts staged combustion and local oxygen enrichment technologies to effectively control the temperature distribution of the flame and significantly reduce the generation of NOx. At the same time, the flue gas recirculation technology effectively reduces the oxygen concentration in the combustion area by recovering and reusing approximately 20% of the flue gas, thereby further suppressing the generation of NOx. This process not only optimizes energy use and improves combustion efficiency but also significantly reduces environmental pollution. In addition, the entire system ensures the accuracy of operation and the controllability of the process through intelligent control.

Description

Technical Field

[0001] The present invention relates to the technical field of air pollutant treatment, and specifically to a low-nitrogen ultra-low emission system and method for an independent heat source grinding station. Background Technique

[0002] In industrial grinding stations, hot blast stoves, as independent heat source equipment, are mainly used to provide high-temperature flue gas required for drying materials. When traditional hot blast stoves burn natural gas, coalbed methane or other fuels, they will inevitably generate various air pollutants including nitrogen oxides (NOx), sulfur dioxide (SO2) and particulate matter. Among them, nitrogen oxides (NOx), as a major type of pollutant, cause particularly serious harm 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] Currently, the common technical approaches to reducing NOx emissions mainly have two types: combustion control and flue gas post-treatment. Combustion control technologies mainly include the application of low-nitrogen burners and the optimization and adjustment of the combustion process, suppressing the generation of NOx by controlling the fuel-air mixing ratio, flame temperature, etc. during the combustion process. Flue gas post-treatment technologies involve using denitration devices such as selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR) technologies to purify the generated NOx.

[0004] For example, a low-nitrogen combustion transformation method and system for a light burning kiln disclosed in the patent number "CN 114060806 A", belonging to the technical field of low-nitrogen combustion, the transformation method includes the installation of natural gas pipelines, air main pipes, and flue gas circulation pipelines; the system includes a light burning kiln, burners, natural gas pipelines, air main pipes, flue gas circulation pipelines, air pipelines, steam pipelines, blowers, induced draft fans, mixers, and purifiers, etc.; this patent specifically conducts a "coal-to-gas" transformation for the light burning kiln, and realizes low-nitrogen combustion, reducing the emissions of NOx, while ensuring the stable operation of the light burning kiln, reducing potential safety hazards, extending the service life, and achieving the effect of clean production. It can significantly reduce the emissions of nitrogen oxides, and the emissions can be reduced by more than 30% compared with general coal-to-gas technologies, and the service life of the pipelines can be extended by more than 1 year.

[0005] However, although these technologies can reduce NOx emissions to a certain extent, they often have some limitations. The following problems exist in the low-nitrogen emissions of independent heat source grinding stations: 1. The SCR technology increases the system complexity and cost; 2. The flue gas recirculation method lacks flexible ratio regulation; 3. The improved burner design cannot simultaneously achieve high efficiency and low emissions, etc. Therefore, researching and developing 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

[0006] In order to solve the problems of the prior art, the present invention provides a low-nitrogen ultra-low emission system and method for an independent heat source grinding station.

[0007] To solve the above technical problems, the present invention is realized through the following technical solutions: In a first aspect, an embodiment of the present application provides a low-nitrogen ultra-low emission system for an independent heat source grinding station, including: a main body of a hot blast stove, a chimney is installed at the top of the main body of the hot blast stove for discharging combustion flue gas, and a burner is installed at one end of the main body of the hot blast stove for burning combustible gas to heat the inside of the main body of the hot blast stove;

[0008] A circulating flue gas pipe, one end of the circulating flue gas pipe is fixedly connected to the chimney, a mixing chamber is fixedly connected to one side of the burner, the other end of the circulating flue gas pipe is connected to the mixing chamber in a through manner, and the circulating flue gas pipe connects the chimney and the mixing chamber in a through manner for guiding a part of the discharged flue gas to be transported to the mixing chamber through the circulating flue gas pipe for recycling. A combustion-supporting gas pipe is fixedly connected to one side of the mixing chamber for transporting combustion-supporting gas into the mixing chamber to be mixed with a part of the flue gas, and further enters the burner to be mixed with the gas and enters the inside of the main body of the hot blast stove to be ignited and used;

[0009] A control system, the control system is composed of a main circuit and a control circuit. The main circuit is used for supplying power to electrical equipment, and the control circuit is composed of a PLC controller, a real-time monitoring module and an output module; it is used for monitoring and controlling the mixing ratio of flue gas, combustion-supporting gas and combustible gas;

[0010] An electromagnetic valve and a fourth gas flowmeter are installed inside the gas pipe, and the fourth gas flowmeter is arranged close to the burner side;

[0011] A flue gas separation device is installed at the middle position of the circulating flue gas pipe, and the flue gas separation device is fixedly connected to the main body of the hot blast stove; a filtering mechanism is installed inside the flue gas separation device, a storage chamber is arranged on one side inside the flue gas separation device, a third variable-speed blower is installed on the other side inside the flue gas separation device, an input hole is arranged at one end of the flue gas separation device, and an output pipe is arranged at the other end of the flue gas separation device. The input hole and the output pipe are respectively connected to the circulating flue gas pipe in a through manner, and the input hole, the storage chamber, the filtering mechanism, the third variable-speed blower and the output pipe are connected in a through manner for transporting flue gas. A third gas flowmeter is installed inside the output pipe for detecting the internal gas flow rate; the filtering mechanism is composed of a motor, a rotating disk, a limiting sliding groove and a filtering cover. The motor is fixedly connected to the flue gas separation device, the output end of the motor is fixedly connected to the rotating disk, a limiting sliding groove is arranged on the outer side of the rotating disk, the number of the limiting sliding grooves is set to be multiple, and the multiple limiting sliding grooves are equidistantly distributed in a circular ring shape inside the rotating disk. A filtering cover is connected to the inner wall of the limiting sliding groove in a limiting sliding manner. The filtering cover is used for intercepting solid particles in the flue gas and storing them inside the storage chamber; a cover plate is installed at the top of the flue gas separation device.

[0012] In the embodiment of the present application, the flue gas is discharged from the chimney at the top of the main body of the hot blast stove. Part of the flue gas is guided to the mixing chamber through the circulating flue pipe, mixed with the combustion-supporting gas, and then enters the burner again for combustion, reducing the intake of fresh air and the oxygen concentration, thereby reducing the generation of nitrogen oxides and environmental pollution.

[0013] In some possible embodiments of the first aspect, a first variable-speed fan and a first gas flow meter are installed inside one end of the circulating flue pipe, and the first gas flow meter is arranged on the side close to 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 on the side close to the mixing chamber.

[0014] The first variable-speed fan and the first gas flow meter in the circulating flue pipe, as well as the second variable-speed fan and the second gas flow meter in the combustion-supporting gas pipe, precisely control the flow rate and mixing ratio of the flue gas and the combustion-supporting gas, ensuring the maximization of combustion efficiency and reducing the generation of nitrogen oxides.

[0015] The flue gas separation device filters the recycled flue gas to remove solid particles therein. The filtering mechanism consists of a rotating disk driven by a motor and a filter cover in a plurality of limit sliding grooves, which is 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 pollutant emissions; the third gas flow meter monitors the gas flow at the output pipe end. When the flow is much lower than 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 replaces it to continue the filtering process. The control system is also configured with an automatic diagnosis and fault handling program to respond to abnormal situations in real time and ensure the safe and stable operation of the system.

[0016] In some possible embodiments 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 inside of 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 inside of 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 main body of the hot blast stove, and the PLC controller is installed inside the control cabinet.

[0017] 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 the flue gas, the combustion-supporting gas and the combustible gas. Key parameters such as gas flow are monitored in real time, and the operating states of each fan and valve are automatically adjusted to achieve low nitrogen emissions.

[0018] In the second aspect, the embodiment of the present application provides a low-nitrogen ultra-low emission method for an independent heat source grinding station, and the specific steps include:

[0019] Step 1: Flue gas recycling and control

[0020] Use a circulating flue gas pipe to guide part of the flue gas from the chimney to the mixing chamber. After mixing with the combustion-supporting gas in the mixing chamber, it re-enters the burner for combustion. This can reduce the intake of fresh air, lower the oxygen concentration, and thus reduce the generation of nitrogen oxides;

[0021] Step 2: Regulation of gas flow rate and ratio

[0022] Through the installed first variable-speed fan, second variable-speed fan, third variable-speed fan and corresponding gas flow meters, accurately control the flow rates and mixing ratios of the flue gas, combustion-supporting gas, and combustible gas to ensure maximum combustion efficiency and reduce the generation of nitrogen oxides;

[0023] Step 3: Flue gas cleaning treatment

[0024] The flue gas separation device filters the recycled flue gas to remove solid particulate matter. The filtered flue gas re-enters the system for recycling, reducing pollutant emissions;

[0025] Step 4: Real-time monitoring and adjustment

[0026] Use the PLC controller and real-time monitoring module to monitor the key parameters during the combustion process in real time, and automatically adjust the operating states of each fan and valve through the output module to achieve low nitrogen emissions;

[0027] Step 5: Maintenance and cleaning

[0028] The third gas flow meter monitors the gas flow rate at the end of the output pipe in real time. When the flow rate is much lower than the preset value, the PLC controller determines that the filter cover is blocked. At this time, it controls the rotation of the output end of the motor by 90 degrees and replaces it with a new filter cover for continuous filtration.

[0029] The PLC controller is also equipped with an automatic diagnosis and fault handling program for real-time response to abnormal situations to ensure the safe and stable operation of the system.

[0030] The key parameters monitored by the real-time monitoring module include flue gas temperature, oxygen content, and nitrogen oxide concentration to more accurately control the combustion process and optimize the low nitrogen emission effect.

[0031] Since the operation method provided by the embodiment of the present application is the method flow of the low-nitrogen ultra-emission 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.

[0032] The beneficial effects of the present invention are:

[0033] 1. By combining a low - nitrogen burner with flue - gas recirculation technology, ultra - low nitrogen oxide emissions in an independent heat - source grinding station are achieved. The low - nitrogen burner adopts staged combustion and local oxygen - enrichment technologies, effectively controlling the temperature distribution of the flame and reducing the generation of NOx. At the same time, through the flue - gas recirculation technology, about 20% of the flue gas is recovered and reused, reducing the oxygen concentration and further inhibiting the generation of NOx. This process not only optimizes energy use, improves combustion efficiency, but also significantly reduces environmental pollution. In addition, the entire system ensures the accuracy of operation and the controllability of the process through intelligent control;

[0034] 2. By adopting a low - nitrogen burner and flue - gas recirculation technology, the NOx emission can be reduced to below 30mg / m^3, far better than the current environmental protection standards, effectively reducing the pollution to the atmospheric environment. The staged combustion and local oxygen - enrichment combustion technologies help reduce the emissions of other pollutants such as sulfur dioxide and particulate matter, further improving air quality;

[0035] 3. This invention does not require large - scale modifications to the existing hot - blast stove. Only the heat - source and flue - gas circulation systems need to be adjusted and optimized, reducing the implementation cost. The flue - gas recirculation technology reduces energy waste by recycling flue gas, improves the overall combustion efficiency, thereby saving fuel consumption and maintenance costs;

[0036] 4. Reducing the emissions of harmful gases such as nitrogen oxides reduces the incidence of air - pollution events such as smog, which is beneficial to improving the respiratory health of the public. Adopting advanced environmental protection technologies can enhance the green image of enterprises, strengthen the trust of consumers and society, and is conducive to the long - term development of enterprises. Brief Description of the Drawings

[0037] Figure 1 is the overall system schematic diagram of the first embodiment of the present invention.

[0038] Figure 2 is the overall system schematic diagram of the second embodiment of the present invention.

[0039] Figure 3 is the schematic diagram of the mixed - gas structure of the first embodiment of the present invention.

[0040] Figure 4 is the schematic diagram of the mixed - gas structure of the second embodiment of the present invention.

[0041] Figure 5 is the schematic diagram of the internal structure of the flue - gas separation device of the second embodiment of the present invention.

[0042] Figure 6 is the schematic diagram of the motor drive structure of the present invention.

[0043] Figure 7 is the schematic diagram of the control connection of the PLC controller of the present invention.

[0044] Figure 8 It is a schematic diagram of the internal structure of the output module of the present invention.

[0045] Figure 9 It is a schematic diagram of the internal structure of the real-time monitoring module of the present invention.

[0046] Figures 1 - 9 In the figure: 1. Main body of the hot blast stove; 11. Control cabinet;

[0047] 2. Burner; 21. Gas pipe; 211. Solenoid valve; 212. Fourth gas flow meter; 3. Chimney;

[0048] 4. Circulation flue pipe; 41. First variable-speed fan; 42. First gas flow meter;

[0049] 5. Mixing chamber; 51. Combustion-supporting gas pipe; 511. Second variable-speed fan; 512. Second gas flow meter;

[0050] 6. Flue gas separation device; 61. Filter mechanism; 611. Motor; 612. Rotating disk; 613. Limit sliding groove; 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;

[0051] 7. PLC controller; 71. Real-time monitoring module; 72. Output module. Detailed implementation manners

[0052] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0053] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "in", "on", "under", "horizontal", "inside", etc. 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, and therefore cannot be construed as a limitation of the present invention.

[0054] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "set", "installed", "connected", and "connected" 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0055] Embodiment 1: Please refer to Figure 1 , Figure 3 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, the embodiment of the present application provides a low-nitrogen ultra-low emission system for an independent heat source grinding station, including: a main body 1 of a hot blast stove, a chimney 3 is installed at the top of the main body 1 of the hot blast stove for discharging combustion flue gas, and a burner 2 is installed at one end of the main body 1 of the hot blast stove for burning combustible gas to heat the inside of the main body 1 of the hot blast stove;

[0056] A circulating flue gas pipe 4, one end of the circulating flue gas pipe 4 is fixedly connected to the chimney 3, a mixing chamber 5 is fixedly connected to one side of the burner 2, the other end of the circulating flue gas pipe 4 is connected to the mixing chamber 5 in a through manner, and the circulating flue gas pipe 4 connects the chimney 3 and the mixing chamber 5 in a through manner for guiding a part of the discharged flue gas to be transported to the mixing chamber 5 through the circulating flue gas pipe 4 for recycling. A combustion-supporting gas pipe 51 is fixedly connected to one side of the mixing chamber 5 for transporting combustion-supporting gas into the mixing chamber 5 to be mixed with a part of the flue gas, and further enters the burner 2 to be mixed with the gas and enters the inside of the main body 1 of the hot blast stove to be ignited and used;

[0057] A control system, the control system is composed of a main circuit and a control circuit. The main circuit is used for supplying 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; it is used for monitoring and controlling the mixing ratio of flue gas, combustion-supporting gas and combustible gas.

[0058] 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 inside of the output module 72 includes a first variable-speed blower 41, a second variable-speed blower 511, a third variable-speed blower 62, a solenoid valve 211 and a motor 611; the inside of the real-time monitoring module 71 includes a first gas flowmeter 42, a second gas flowmeter 512, a third gas flowmeter 67 and a fourth gas flowmeter 212. A control cabinet 11 is installed on one side of the main body 1 of the hot blast stove, and the PLC controller 7 is installed inside the control cabinet 11.

[0059] In this way, the main body 1 of the hot blast stove, as the core component, heats the materials through the high-temperature flame generated by the burner 2 inside. The burner 2 is located at one end of the main body 1 of the hot blast stove 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 main body of the hot blast stove for discharging the flue gas generated by combustion;

[0060] To reduce the emission of nitrogen oxides, the system adopts the design of the circulating flue pipe 4. One end of the circulating flue pipe 4 is fixedly connected to the chimney 3, and the other end is connected to the mixing chamber 5 in a penetrating manner. In this way, part of the flue gas can be guided through the circulating flue pipe 4 to the mixing chamber 5 for recycling. Inside the mixing chamber 5, the combustion-supporting gas pipe 51 transports the combustion-supporting gas in, which is mixed with part of the flue gas. This mixed gas further enters the burner to be mixed with the combustible gas and finally enters the inside of the main body 1 of the hot blast stove to be ignited and used.

[0061] The control system is the brain of the whole system and is composed of a main circuit and a control circuit. The main circuit is responsible for supplying power to the electrical equipment, while the control circuit is composed of a PLC controller, a real-time monitoring module, and an output module. The control system can monitor the mixing ratio of the flue gas, the combustion-supporting gas, and the combustible gas in real time and adjust it as needed to ensure the stable operation of the system and low nitrogen emissions.

[0062] A first variable-speed blower 41 and a first gas flowmeter 42 are installed inside one end of the circulating flue pipe 4, and the first gas flowmeter 42 is arranged on the side close to the mixing chamber 5. A second variable-speed blower 511 and a second gas flowmeter 512 are installed inside the combustion-supporting gas pipe 51, and the second gas flowmeter 512 is arranged on the side close to the mixing chamber 5. An electromagnetic valve 211 and a fourth gas flowmeter 212 are installed inside the gas pipe 21, and the fourth gas flowmeter 212 is arranged on the side close to the burner 2.

[0063] In the first embodiment, the core of the low-nitrogen ultra-low emission system of the independent heat source grinding station is the main body 1 of the hot blast stove. The combustible gas is ignited by the burner 2 to generate a high-temperature flame for heating the materials. To reduce the emission of nitrogen oxides (NOx), the system adopts the design of the circulating flue pipe 4 to reintroduce part of the flue gas into the mixing chamber 5 for recycling. This not only improves the thermal efficiency but also reduces the emission of harmful gases.

[0064] The control system is composed of a main circuit and a control circuit. Among them, the PLC controller 7 is responsible for monitoring and adjusting the mixing ratio of the flue gas, the combustion-supporting gas, and the 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.

[0065] Embodiment Two: Please refer to Appendix Figure 2 , Figure 4 , Figure 5 andFigure 6 As shown in the figure, a flue gas separation device 6 is installed at the middle position of the circulating flue pipe 4, and the flue gas separation device 6 is fixedly connected to the main body 1 of the hot blast stove; a filtering mechanism 61 is installed inside the flue gas separation device 6, a storage chamber 63 is provided on one side inside the flue gas separation device 6, a third variable-speed blower 62 is installed on the other side inside 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. The input hole 64 and the output pipe 66 are respectively connected to the circulating flue pipe 4 in a penetrating manner, and the input hole 64, the storage chamber 63, the filtering mechanism 61, the third variable-speed blower 62 and the output pipe 66 are connected in a penetrating manner for conveying flue gas. A third gas flowmeter 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 sliding groove 613 and a filtering cover 614. The motor 611 is fixedly connected to the flue gas separation device 6, the output end of the motor 611 is fixedly connected to the rotating disk 612, a limiting sliding groove 613 is arranged on the outer side of the rotating disk 612, the number of the limiting sliding grooves 613 is set to be multiple, and the multiple limiting sliding grooves 613 are equidistantly distributed in a circular ring shape inside the rotating disk 612. The inner wall of the limiting sliding groove 613 is connected to the filtering cover 614 in a limiting sliding manner. The filtering cover 614 is used for intercepting solid particles in the flue gas and storing them inside the storage chamber 63; a cover plate 65 is installed at the top of the flue gas separation device 6.

[0066] Compared with the first embodiment, in this embodiment, by adding a flue gas separation device 6 in the circulating flue pipe 4, the environmental protection performance of the system is further enhanced. A filtering mechanism 61 is provided inside the flue gas separation device 6, including a motor 611, a rotating disk 612, a limiting sliding groove 613 and a filtering cover 614. These components work together to effectively intercept solid particles in the flue gas and store them in the storage chamber 63. This setting helps to reduce the solid waste generated during combustion, reduce the particulate matter emissions in the discharged 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 during the combustion of the burner 2, ensuring the combustion effect.

[0067] The flue gas separation device 6 further includes a motor 611 and four filtering covers 614. When the filtering cover 614 adheres to particulate matter and hinders the flow of flue gas, at this time, the third gas flowmeter 67 is triggered, and the trigger signal is transmitted to the PLC controller, thereby controlling the operation of the motor 611 to drive the filtering cover to rotate 90 degrees, and further driving a new filtering cover 614 to continue filtering and using.

[0068] The flue gas separation device 6 further includes a third variable-speed blower 62 and a third gas flowmeter 67 for adjusting the flow rate of the treated flue gas to ensure the stability and controllability of the flue gas flow. The addition of the cover plate 65 may be used to protect the internal machinery from environmental factors, and at the same time it is also convenient for maintenance and repair.

[0069] Low-nitrogen ultra-low emission method for an independent heat source grinding station, the specific steps include:

[0070] Step 1: Flue gas recycling and control

[0071] Use the circulating flue gas pipe 4 to guide part of the flue gas from the chimney 3 to the mixing chamber 5, where it is mixed with the combustion-supporting gas and then 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;

[0072] Step 2: Regulation of gas flow rate and ratio

[0073] Through the installed first variable-speed fan 41, second variable-speed fan 511, third variable-speed fan 62 and the corresponding gas flow meters, accurately control the flow rates and mixing ratios of the flue gas, combustion-supporting gas, and combustible gas to ensure maximum combustion efficiency while reducing the generation of nitrogen oxides;

[0074] Step 3: Flue gas cleaning treatment

[0075] The flue gas separation device 6 filters the recycled flue gas to remove the solid particulate matter therein. The filtered flue gas re-enters the system for recycling, reducing pollutant emissions;

[0076] Step 4: Real-time monitoring and adjustment

[0077] Use the PLC controller 7 and the real-time monitoring module 71 to monitor the key parameters during the combustion process in real time, and automatically adjust the operating states of each fan and valve through the output module 72 to achieve low-nitrogen emissions;

[0078] Step 5: Maintenance and cleaning

[0079] The third gas flow meter 67 monitors the gas flow rate at the end of the output pipe 66 in real time. When the flow rate is much lower than the preset value 32, the PLC controller 7 determines that the filter cover 614 is blocked. At this time, it controls the motor 611 to rotate the control output end by ninety degrees and replaces it with a new filter cover 614 for continuous filtration. The PLC controller 7 is also equipped with an automatic diagnosis and fault handling program for real-time response to abnormal situations to ensure the safe and stable operation of the system.

[0080] The key parameters monitored by the real-time monitoring module 71 include flue gas temperature, oxygen content, and nitrogen oxide concentration to more accurately control the combustion process and optimize the low-nitrogen emission effect.

[0081] In summary, the problem of nitrogen oxide (NOx) emissions from independent heat source grinding stations has become a key concern in the environmental protection field. With the increasingly strict national and local policies, traditional combustion technologies are no longer able to meet the new emission standards. To address this challenge, the present invention proposes an innovative solution that combines a low-nitrogen burner and flue gas recirculation technology (FGR).

[0082] First, the low-nitrogen burner precisely controls the ratios of natural gas, combustion-supporting air, and recycled flue gas to achieve staged combustion and local oxygen-rich combustion, thereby effectively reducing the generation of NOx. This burner is operated using an independent control cabinet, ensuring the stability and continuity of the combustion process.

[0083] Second, the flue gas recirculation technology recovers a portion of the flue gas in the flue (about 20%) and mixes it with the combustion-supporting air before reintroducing it into the furnace for combustion. This not only changes the temperature distribution of the flame, reducing the generation of NOx, but also reduces NOx emissions to below 30 mg / m^3, far lower than the current standards.

[0084] The significant advantage of the present invention is that it only requires modification and adjustment of the heat source and flue gas circulation system, without the need for large-scale changes to the hot blast stove itself, greatly reducing the retrofit 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 contributes to safeguarding human health.

[0085] Overall, the research and application of this technology for stable and continuous ultra-low emissions of nitrogen oxide concentration in independent heat source grinding stations demonstrate the possibility and potential of achieving ultra-low emissions in the field of industrial combustion.

[0086] The above description of the present invention and its implementation manners is not restrictive. What is shown throughout the text is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. In summary, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, creatively design structural manners and embodiments similar to this technical solution, they shall fall within 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 on the outer side of the rotating disk (612); 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 2 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 3 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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