Anti-skinning optimization method for preheater system of denitrification furnace for cement production

Abstract

The invention relates to the technical field of cement clinker calcination, in particular to an anti-skinning optimization method for a denitrification furnace preheater system for cement production. According to the technical scheme, the anti-skinning optimization method for the preheater system of the denitrification furnace for cement production comprises the working process of structure transformation of an eccentric cone discharging pipe; according to the invention, the inner diameter of the eccentric cone blanking pipe is enlarged to 1200mm, so that the designed flow is increased to 120% of the original level, and the possibility of deposition of harmful components is fundamentally reduced; a high-temperature-resistant 304 stainless steel material is adopted to replace an original part, and a microcrystal plate lining is laid on a pipe section below the expansion joint, so that the corrosion resistance and the skinning resistance of the pipeline are greatly improved; besides, the inclination angle of the discharging pipe is calibrated to 22 degrees through the laser gradienter, the laser range finder is installed to monitor the material stacking height in real time, dynamic early warning of the material blocking risk is achieved, the skinning problem caused by insufficient pipe diameter and material aging is effectively solved, and meanwhile the manual blockage clearing frequency is reduced.

Description

Technical Field

[0001] This invention relates to the field of cement clinker calcination technology, and in particular to an optimization method for preventing scaling in a denitrification furnace preheater system used in cement production. Background Technology

[0002] In recent years, with the tightening of national environmental protection policies and the increase in control efforts, various localities have also imposed stricter requirements on nitrogen oxide emissions from the cement industry. To this end, the state has successively introduced ultra-low emission standards. In response to the national call, Shaanxi Beiyuan Group Cement Co., Ltd. has initiated and upgraded its ultra-low emission projects within the industry. After the upgrade, the denitrification furnace system was put into operation on the carbide slag production line for the first time. During the operation, problems such as severe scaling of the denitrification furnace, frequent eccentric cone blockage, many unplanned shutdowns, and low free calcium qualification rate occurred one after another, making production unstable. The above problems could not be solved by operational adjustments, and further optimization of the system was imminent.

[0003] Existing methods for optimizing the anti-scaling of denitrification furnace preheater systems have significant shortcomings in pipeline design and material application. These shortcomings are mainly manifested in the small diameter of the eccentric cone feed pipe and the unreasonable selection of refractory materials. The inner diameter of the feed pipe is only 1000mm, which makes it easy for harmful components in the carbide slag to deposit in the pipe and form scalded material, frequently causing blockages. At the same time, the ordinary anti-scaling castable used on the inner wall cannot effectively resist the corrosion of components such as sulfur and chlorine. Components such as flap valves and expansion joints are jammed due to scaling, leading to unplanned shutdowns.

[0004] Addressing existing methods for preventing scaling in denitrification furnace preheater systems, this paper examines significant shortcomings in pipe design and material application. These shortcomings primarily stem from the small diameter of the eccentric cone feed pipe and inappropriate refractory material selection. The feed pipe's inner diameter is only 1000mm, leading to the easy deposition of harmful components from the carbide slag within the pipe, forming scale and frequently causing blockages. Furthermore, the ordinary anti-scaling castable used for the inner wall is ineffective against the erosion of sulfur and chlorine, causing unplanned shutdowns due to scale jamming of components such as flap valves and expansion joints. This proposed solution first increases the inner diameter of the eccentric cone feed pipe to 1200mm, significantly improving material throughput and increasing the design flow rate to 120% of the original level. This fundamentally reduces the possibility of harmful component deposition. Secondly, the original components are replaced with high-temperature resistant 304 stainless steel, and microcrystalline plates are laid as linings in the pipe section below the expansion joint. The corrosion resistance and anti-scaling performance of the pipeline are significantly improved by using a staggered dry-laying process and filling the joints with high-temperature resistant mortar. In addition, the tilt angle of the feed pipe is calibrated to 22° using a laser level, and a laser rangefinder is installed to monitor the material accumulation height in real time, realizing dynamic early warning of the risk of material blockage. This not only effectively solves the scaling problem caused by insufficient pipe diameter and material aging, but also reduces system resistance by optimizing the flow field distribution, extends the service life of equipment, reduces the frequency of manual unblocking, and significantly improves production continuity and safety. Summary of the Invention

[0005] To overcome the shortcomings of existing anti-scaling optimization methods in denitrification furnace preheater systems, the denitrification furnace preheater system has significant deficiencies in pipeline design and material application. These deficiencies are mainly manifested in the small diameter of the eccentric cone feed pipe and the unreasonable selection of refractory materials. The inner diameter of the feed pipe is only 1000mm, which makes it easy for harmful components in carbide slag to deposit in the pipe and form scalded blocks, frequently causing material blockage. At the same time, the ordinary anti-scaling castable used on the inner wall cannot effectively resist the corrosion of components such as sulfur and chlorine. The flap valve, expansion joint and other components are stuck due to scaling, causing unplanned shutdowns.

[0006] The technical solution of this invention is: an optimization method for preventing scaling in a denitrification furnace preheater system used in cement production, comprising the following steps:

[0007] S11: By increasing the pipe diameter, replacing the lining with high-temperature resistant microcrystalline material, and adding a pressure measuring device, the material throughput capacity is improved and the crusting status is monitored in real time; S12: Remove redundant pipes, adjust the position of the material feeding box, replace the microcrystalline liner, and integrate a DCS with a pressure sensor to achieve visualized control of material feeding efficiency and operating conditions; S13: Reconstruct the cross-sectional shape and airflow guiding structure of the air outlet, add an air cannon array, and coordinate with DCS pressure monitoring to eliminate localized material accumulation and uneven airflow. S14: Optimize the top plate inclination angle and the guide vane material to increase the ventilation cross-sectional area, reduce system resistance, and improve thermal stability; S15: Replaces the straight nozzle with a fan-shaped nozzle, precisely positioning the spray points, and combines solenoid valve control for efficient cleaning of crusted areas; S16: In high-temperature areas prone to skin formation, microcrystalline boards are completely replaced. Through staggered dry-laying technology and wear monitoring, the equipment life is extended and manual intervention is reduced. S17: Deploy differential pressure transmitters and a three-level alarm mechanism, with data directly connected to the DCS for material blockage early warning and dynamic adjustment of process parameters; S18: Increase the cross-sectional area of ​​the pipeline, optimize the flow field distribution, and combine variable frequency fans with CFD simulation to ensure balanced airflow and energy-saving operation of the system; S19: Establish an operational database and expert control system to achieve adaptive adjustment of thermal regime and maximize production capacity through multi-parameter coupling analysis.

[0008] As a preferred option, the modification of the eccentric cone feed tube structure includes the following steps: S21: Increase the inner diameter of the eccentric cone feed pipe from 1000mm to 1200mm to improve the material throughput to 120% of the design flow rate, while maintaining a pipe wall thickness of 8mm and an inner wall roughness ≤ Ra0.8; S22: Remove the original flap valve and expansion joint, and replace them with high-temperature resistant 304 stainless steel. The sealing test requires a leakage rate of ≤0.1L / min at a pressure of 0.5kPa. S23: The inner wall of the pipe section 300mm below the expansion joint shall be covered with a microcrystalline plate with a thickness of 20±2mm and a surface roughness ≤Ra0.4. The joints shall be filled with high-temperature resistant mortar. S24: A DN50 air cannon interface is reserved 150mm above the expansion joint, and a high-temperature resistant 316L stainless steel fan-shaped nozzle is installed to match it, with a spray angle of 60° and a flow coefficient Cv=5.0; S25: The inclination angle of the feed pipe is adjusted to 22°, with an angle error of ≤±1° with the horizontal plane. A laser level is used for calibration, and the material's self-flow velocity is checked to ensure it is ≥0.8m / s. S26: Install a laser rangefinder to monitor the material accumulation height in the feed pipe in real time, set the alarm threshold to 70% of the pipe diameter, and the data acquisition frequency is 1 time / second; S27: Use an endoscope to check the wear of the tube wall every quarter. Replace the microcrystalline plate immediately when the wear exceeds 5mm, and record the location and extent of the wear.

[0009] As a preferred option, the optimization of the C4 feed pipe system includes the following steps: S31: Cut and dismantle the spare feed pipe and secondary distribution valve of the mixing chamber, weld the sealing plate with a thickness of not less than 10mm, and perform 100% X-ray inspection after welding, with a defect rate of ≤1%; S32: Move the entire feeding box of the denitrification furnace upward by 1000mm. After adjustment, the vertical distance between the feeding point and the distribution valve is 800mm, and the angle of the feeding plate is adjusted from 5° to 25°. S33: The section of pipe below the flap valve of the denitrification furnace feed pipe from C4 should be replaced with a microcrystalline lining. The joint width should be controlled at 2-3mm, the installation gap ≤3mm, and the staggered dry-laying method should be used for construction. S34: Install one pressure sensor on each of the feed pipes from C4 to the decomposition furnace and the denitrification furnace, with a range of 0-5000Pa and an accuracy of ±0.2%FS. The signal is connected to the DCS system. S35: Check the torque of the flange connection bolts of the feed pipe monthly to ensure that the preload of the M16 bolts reaches 180 N·m, and verify it using a torque wrench; S36: Use compressed air to blow clean the inner wall of the feed pipe weekly, with the pressure controlled at 0.6MPa and the blowing time lasting for 3 minutes, focusing on cleaning the accumulated material at the joints; S37: Adjust the deviation between the center line of the feed pipe and the axis of the denitrification furnace to ≤5mm, and use a theodolite for three-dimensional spatial positioning calibration to check the centering accuracy.

[0010] As a preferred option, the following steps are included when improving the duct outlet: S41: Change the cross-section of the tertiary air duct outlet from a φ800mm circular shape to a flat structure with a width of 1200mm and a height of 400mm, increasing the ventilation area by 40% and controlling the air velocity at 8-12m / s; S42: The bottom of the air outlet is chamfered at 45° with a chamfer radius R=100mm, processed using a CNC plasma cutting machine, with a surface roughness ≤Ra3.2; S43: Remove the eccentric cone pressure measuring ring, weld and seal it, then perform surface polishing to achieve a roughness of Ra1.6. The sealing test pressure is 1.5 times the design pressure. S44: Two air cannons are symmetrically installed at 1 / 3 height of the air outlet, with a nozzle spacing of 500mm and an adjustable spray angle range of ±15°. The material is Hastelloy C276. S45: Monthly inspection of air outlet wind speed distribution, using a hot-wire anemometer to measure at cross-sectional grid points with a grid spacing of 200mm, to check if the standard deviation of wind speed is ≤0.5m / s; S46: The air outlet guide plate is replaced with a precast refractory castable component with a thickness of 150mm. After installation, it is baked and cured at 1100℃, with the baking curve consisting of three stages of temperature increase. S47: Check the material accumulation at the air outlet every shift. When the material accumulation thickness exceeds 50mm, start the air cannon to clean it. Record the cleaning cycle to the DCS system.

[0011] Preferably, the following steps are included when reconstructing the outlet pipe of the denitrification furnace: S51: Modify the top plate of the denitrification furnace outlet to be inclined at 30° to the horizontal plane, process it with a laser cutting machine, and ensure that the bevel angle error is ≤1°. Perform PT testing after welding. S52: The baffle plate at the connection between the outlet and the mixing chamber is replaced with refractory castable, with dimensional accuracy controlled within ±2mm, installation gap ≤3mm, and curing for 72 hours after pouring; S53: Replace the metal spiral wound gasket at the flange connection of the outlet pipe with a 304 stainless steel strip + flexible graphite material, with a compression ratio controlled at 15-20%, and uniform bolt preload; S54: Weld a wear-resistant liner, 8mm thick, made of NM400 wear-resistant steel plate, to the elbow of the outlet pipe. After welding, perform UT testing, with a defect rate ≤0.5%. S55: Monthly inspection of the displacement of the expansion joint of the outlet pipeline; lateral displacement ≤20mm, axial displacement ≤15mm; real-time monitoring using displacement sensors. S56: The insulation layer of the outlet pipeline is made of aluminum silicate fiber blanket with a density of 200kg / m³ and a thickness of 150mm, with an outer protective layer of 0.8mm aluminum plate, and the joints are sealed. S57: Conduct stress analysis on the export pipeline every quarter, using ANSYS software for modeling, and check whether the maximum stress is ≤ 80% of the material's allowable stress. Archive the analysis results.

[0012] Preferably, the air cannon nozzle upgrade includes the following steps: S61: Replace 27 straight nozzles at the inlet and eccentric cone of the denitrification furnace with fan-shaped nozzles, adjust the spray angle to 60°, the flow coefficient Cv=5.0, and the material to be 316L stainless steel; S62: The air cannon's air tank pressure is set to 0.8MPa, and it is equipped with an automatic drain valve. Condensate is drained once per shift, and the drainage volume is recorded in the log. S63: Nozzle installation position error ≤10mm laterally, ≤5mm longitudinally, calibrated using a laser positioning instrument, with the spray direction forming a 30° angle with the material flow direction; S64: Monthly test the nozzle outlet flow rate using an anemometer at a distance of 100mm from the nozzle to check if the flow rate is ≥200m / s and if the flow rate deviation is ≤±5%; S65: Two air cannons are added between the outlet of the tertiary air duct and the outlet of the denitrification furnace, with a spacing of 1500mm and adjustable spray direction. The material is silicon carbide ceramic composite. S66: An air cannon is added to both the eccentric cone straight section and the smoke chamber expansion joint, with the nozzle centerline forming a 30° angle with the pipe wall and a coverage radius ≥ 500mm; S67: Two air cannons are added to the upper conical section of the mixing chamber, which are controlled by solenoid valves with a response time of ≤0.2 seconds and the injection frequency is linked to the material flow rate.

[0013] Preferably, the following steps are included when applying microcrystalline materials in depth: S71: The lining of key components is replaced with a microcrystalline board, 25mm thick, with a flexural strength ≥40MPa and a temperature resistance range ≤1200℃; S72: Microcrystalline panels are installed using a staggered dry-laying method, with joint width controlled at 2-3mm, and filled with high-temperature resistant mortar, which has a temperature resistance of ≥1300℃. S73: Monthly inspection of the surface roughness of the microcrystalline board, using a portable roughness meter to measure whether Ra is ≤0.4, marking worn areas and replacing them first; S74: Establish a wear record for microcrystalline materials, recording the wear amount of each plate. Replace the plate when the thickness loss exceeds 30%, and incorporate the replacement cycle prediction model into the DCS. S75: Microcrystalline board curing adopts a steam curing process, with temperature controlled at 50±5℃, humidity ≥95%, and curing time of 72 hours, divided into three stages of heating and cooling; S76: Operators receive training on the properties of microcrystalline materials, mastering the thermal shock resistance and corrosion resistance performance indicators, with a 100% training pass rate; S77: The anti-scabbing performance of microcrystalline materials will be evaluated quarterly. The effect will be quantified by the scale of the scale and the frequency of cleaning. The evaluation results will be linked to performance appraisal.

[0014] As a preferred option, the intelligent transformation of the pressure measurement system includes the following steps: S81: Install a differential pressure transmitter 500mm above the flap valve, with a range of 0-1000Pa, accuracy of 0.1%FS, signal input to the DCS system, and response time ≤0.5 seconds; S82: The DCS system is configured with three alarm levels: Level 1 alarm 500Pa, Level 2 alarm 700Pa, and Level 3 alarm 900Pa. Alarm information is pushed to mobile terminals. S83: The pressure measuring device shall be calibrated monthly using a standard pressure source at 0%, 50%, and 100% of the measuring range for three-point verification. The error shall be ≤0.2%FS, and the calibration record shall be archived. S84: The pressure testing pipeline uses φ12×2mm stainless steel pipe with a slope of ≥5%. A drain valve is installed at the lowest point, and the draining cycle is once a day. The draining volume is recorded in the log. S85: Operator training will enable them to master pressure trend analysis skills and determine the location of material blockage through pressure curves. The training content includes case analysis and practical operation. S86: Establish a historical database of pressure data, with a sampling period of 1 second, a storage period of ≥1 year, and data backup to a cloud server; S87: Develop pressure data analysis software to achieve material blockage early warning and fault diagnosis functions, with an early warning accuracy rate of ≥95% and automatic generation of diagnostic reports.

[0015] Preferably, when expanding or upgrading a ventilation system, the following steps are included: S91: The cross-sectional area of ​​the denitrification furnace outlet pipe is increased from 0.5m² to 0.7m², and it is machined using a CNC bending machine with an ovality ≤1%. After welding, it undergoes PT testing with a defect rate ≤0.5%. S92: After the modification of the tertiary air duct outlet, the ventilation area increased to 1.2m², the wind speed was controlled at 8-12m / s, the air volume adjustment range was ±10%, and a variable frequency fan was used for control; S93: The total ventilation volume of the system is increased to 180,000 m³ / h, equipped with a variable frequency fan to achieve stepless air volume adjustment, with a fan efficiency of ≥85% and noise level of ≤85dB; S94: Monthly system resistance testing, using a Pitot tube at a measuring point grid with a grid spacing of 500mm, the total resistance is ≤4500Pa, and the resistance distribution is uniform; S95: The interior of the ventilation duct is polished to a surface roughness of Ra3.2 to reduce material adhesion. After polishing, a cleanliness test is performed, and particulate matter residue is ≤0.1g / m². S96: Install an air volume regulating valve with an opening control accuracy of ±2% to achieve balanced air volume distribution in each branch. The regulating valve actuator uses an electric actuator with a response time of ≤2 seconds. S97: Conduct CFD flow field simulations every quarter to optimize pipeline layout, eliminate low-speed vortex regions, and compare simulation results with actual measurement data with an error of ≤5%.

[0016] Preferably, the dynamic optimization of process parameters includes the following steps: S1001: Establish an operating parameter database to record key parameters such as air volume, temperature, and pressure. The sampling period is 1 minute, and the data is stored in a real-time database. Historical data is retained for ≥3 years. S1002: Develop an expert control system that automatically adjusts operating parameters based on changes in material composition and output, with an adjustment range of ≤±5% and a system response time of ≤30 seconds; S1003: Perform thermal calibration monthly, measuring system thermal efficiency, unit energy consumption, and other indicators. The thermal efficiency target is ≥85%, and the unit energy consumption is ≤105kJ / kg. The calibration report shall be submitted to management. S1004: Operators receive training on dynamic parameter adjustment, mastering the skill of adjusting the feed rate according to pressure changes. The training includes simulation exercises and practical assessments, with a 100% pass rate. S1005: Establish a crusting early warning model, and achieve early intervention through multi-parameter coupled analysis of temperature, pressure and composition, with an early warning lead time of ≥1 hour and an accuracy rate of ≥90%; S1006: Conduct system capability testing quarterly to verify operational stability under 120% load conditions, with key parameter fluctuations ≤ ±3%, and archive test reports; S1007: Benchmark against leading companies in the industry, continuously improve operating procedures, and enhance system reliability.

[0017] The beneficial effects of this invention are: 1. Existing methods for optimizing the anti-scaling mechanism of the denitrification furnace preheater system: The denitrification furnace preheater system has significant deficiencies in pipeline design and material application, mainly manifested in the small diameter of the eccentric cone feed pipe and the unreasonable selection of refractory materials. The inner diameter of the feed pipe is only 1000mm, which leads to the easy deposition of harmful components in the carbide slag in the pipe, forming scale blocks and frequently causing material blockage. At the same time, the ordinary anti-scaling castable used on the inner wall cannot effectively resist the corrosion of components such as sulfur and chlorine. Components such as flap valves and expansion joints are jammed due to scale, causing unplanned shutdowns. This solution first increases the inner diameter of the eccentric cone feed pipe to 1200mm, significantly improving the material throughput capacity and increasing the design flow rate to 120% of the original level. This fundamentally reduces the possibility of harmful component deposition. Secondly, the original components are replaced with high-temperature resistant 304 stainless steel, and microcrystalline plates are laid as linings in the pipe section below the expansion joint. The joints are filled with high-temperature resistant mortar through a staggered dry-laying process, which significantly improves the corrosion resistance and anti-scaling performance of the pipeline. In addition, the tilt angle of the feed pipe is calibrated to 22° using a laser level, and a laser rangefinder is installed to monitor the material accumulation height in real time, realizing dynamic early warning of the risk of material blockage. This not only effectively solves the scaling problem caused by insufficient pipe diameter and material aging, but also reduces system resistance by optimizing the flow field distribution, extends the service life of equipment, reduces the frequency of manual unblocking, and significantly improves production continuity and safety. 2. Existing methods for optimizing the anti-scaling process of the denitrification furnace preheater system have structural shortcomings in ventilation and airflow control. These shortcomings are mainly manifested in the unreasonable design of the tertiary air duct outlet and the insufficient ventilation cross-sectional area at the denitrification furnace outlet. The original tertiary air duct outlet has a circular structure without a chamfered bottom, which makes it easy for material to accumulate at the bottom of the outlet after the scald falls off. At the same time, the circular cross-section causes uneven airflow distribution, and the local low wind speed exacerbates the risk of material powder settling. The top plate of the denitrification furnace outlet is horizontally designed with a minimum net ventilation area of ​​only 5.6㎡. The small ventilation cross-sectional area causes abrupt changes in flue gas flow velocity, and material powder is prone to settling into the eccentric cone and forming a blockage. This solution restructures the outlet cross-sectional shape and flow guiding structure, changing the tertiary air duct outlet to a flat structure of 1200mm wide × 400mm high, increasing the ventilation area by 40% and controlling the air velocity at 8-12m / s, effectively eliminating the problem of uneven airflow distribution. Simultaneously, the top plate of the denitrification furnace outlet is changed to be inclined at 30° to the horizontal plane, and the ventilation cross-sectional area is expanded. Combined with refractory castable guide plates to optimize the tangential airflow direction, the risk of material powder deposition is significantly reduced. Furthermore, by using variable frequency fans and CFD simulation technology to achieve balanced airflow regulation, the total system ventilation volume is increased to 180,000m³ / h, with fan efficiency ≥85% and noise ≤85dB. This not only solves the problems of crusting and material blockage caused by poor ventilation but also reduces system resistance and improves thermal stability by optimizing the flow field distribution, achieving energy-saving operation and maximizing production capacity. Attached Figure Description

[0018] Figure 1 The diagram shown is a schematic flowchart of the framework of an optimization method for preventing scaling in a denitrification furnace preheater system for cement production according to the present invention. Figure 2 The diagram shown is a schematic of the process for modifying the eccentric cone feed pipe structure of an optimization method for preventing scaling in a denitrification furnace preheater system for cement production, according to the present invention. Figure 3 The diagram shown is a schematic of the optimization process of the C4 feed pipe system for the anti-scaling optimization method of the denitrification furnace preheater system for cement production according to the present invention. Figure 4 The diagram shown is a schematic of the process for improving the outlet of the tertiary air duct of an optimization method for preventing scaling in a denitrification furnace preheater system for cement production, according to the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Please see Figure 1-4 This invention provides an embodiment: an optimization method for preventing scaling in a denitrification furnace preheater system used in cement production, comprising the following steps: S11: By increasing the pipe diameter, replacing the lining with high-temperature resistant microcrystalline material, and adding a pressure measuring device, the material throughput capacity is improved and the crusting status is monitored in real time; S12: Remove redundant pipes, adjust the position of the material feeding box, replace the microcrystalline liner, and integrate DCS with pressure sensors to achieve visualized control of material feeding efficiency and operating conditions; S13: Reconstruct the cross-sectional shape and airflow guiding structure of the air outlet, add an air cannon array, and coordinate with DCS pressure monitoring to eliminate localized material accumulation and uneven airflow. S14: Optimize the top plate inclination angle and the guide vane material to increase the ventilation cross-sectional area, reduce system resistance, and improve thermal stability; S15: Replaces the straight nozzle with a fan-shaped nozzle, precisely positioning the spray points, and combines solenoid valve control for efficient cleaning of crusted areas; S16: In high-temperature areas prone to skin formation, microcrystalline boards are completely replaced. Through staggered dry-laying technology and wear monitoring, the equipment life is extended and manual intervention is reduced. S17: Deploy differential pressure transmitters and a three-level alarm mechanism, with data directly connected to the DCS for material blockage early warning and dynamic adjustment of process parameters; S18: Increase the cross-sectional area of ​​the pipeline, optimize the flow field distribution, and combine variable frequency fans with CFD simulation to ensure balanced airflow and energy-saving operation of the system; S19: Establish an operational database and expert control system to achieve adaptive adjustment of thermal regime and maximize production capacity through multi-parameter coupling analysis.

[0021] As a preferred option, the modification of the eccentric cone feed tube structure includes the following steps: S21: Increase the inner diameter of the eccentric cone feed pipe from 1000mm to 1200mm to improve the material throughput to 120% of the design flow rate, while maintaining a pipe wall thickness of 8mm and an inner wall roughness ≤ Ra0.8; S22: Remove the original flap valve and expansion joint, and replace them with high-temperature resistant 304 stainless steel. The sealing test requires a leakage rate of ≤0.1L / min at a pressure of 0.5kPa. S23: The inner wall of the pipe section 300mm below the expansion joint shall be covered with a microcrystalline plate with a thickness of 20±2mm and a surface roughness ≤Ra0.4. The joints shall be filled with high-temperature resistant mortar. S24: A DN50 air cannon interface is reserved 150mm above the expansion joint, and a high-temperature resistant 316L stainless steel fan-shaped nozzle is installed to match it, with a spray angle of 60° and a flow coefficient Cv=5.0; S25: The inclination angle of the feed pipe is adjusted to 22°, with an angle error of ≤±1° with the horizontal plane. A laser level is used for calibration, and the material's self-flow velocity is checked to ensure it is ≥0.8m / s. S26: Install a laser rangefinder to monitor the material accumulation height in the feed pipe in real time, set the alarm threshold to 70% of the pipe diameter, and the data acquisition frequency is 1 time / second; S27: Use an endoscope to check the wear of the tube wall every quarter. Replace the microcrystalline plate immediately when the wear exceeds 5mm, and record the location and extent of the wear.

[0022] As a preferred option, the optimization of the C4 feed pipe system includes the following steps: S31: Cut and dismantle the spare feed pipe and secondary distribution valve of the mixing chamber, weld the sealing plate with a thickness of not less than 10mm, and perform 100% X-ray inspection after welding, with a defect rate of ≤1%; S32: Move the entire feeding box of the denitrification furnace upward by 1000mm. After adjustment, the vertical distance between the feeding point and the distribution valve is 800mm, and the angle of the feeding plate is adjusted from 5° to 25°. S33: The section of pipe below the flap valve of the denitrification furnace feed pipe from C4 should be replaced with a microcrystalline lining. The joint width should be controlled at 2-3mm, the installation gap ≤3mm, and the staggered dry-laying method should be used for construction. S34: Install one pressure sensor on each of the feed pipes from C4 to the decomposition furnace and the denitrification furnace, with a range of 0-5000Pa and an accuracy of ±0.2%FS. The signal is connected to the DCS system. S35: Check the torque of the flange connection bolts of the feed pipe monthly to ensure that the preload of the M16 bolts reaches 180 N·m, and verify it using a torque wrench; S36: Use compressed air to blow clean the inner wall of the feed pipe weekly, with the pressure controlled at 0.6MPa and the blowing time lasting for 3 minutes, focusing on cleaning the accumulated material at the joints; S37: Adjust the deviation between the center line of the feed pipe and the axis of the denitrification furnace to ≤5mm, and use a theodolite for three-dimensional spatial positioning calibration to check the centering accuracy.

[0023] As a preferred option, the following steps are included when improving the duct outlet: S41: Change the cross-section of the tertiary air duct outlet from a φ800mm circular shape to a flat structure with a width of 1200mm and a height of 400mm, increasing the ventilation area by 40% and controlling the air velocity at 8-12m / s; S42: The bottom of the air outlet is chamfered at 45° with a chamfer radius R=100mm, processed using a CNC plasma cutting machine, with a surface roughness ≤Ra3.2; S43: Remove the eccentric cone pressure measuring ring, weld and seal it, then perform surface polishing to achieve a roughness of Ra1.6. The sealing test pressure is 1.5 times the design pressure. S44: Two air cannons are symmetrically installed at 1 / 3 height of the air outlet, with a nozzle spacing of 500mm and an adjustable spray angle range of ±15°. The material is Hastelloy C276. S45: Monthly inspection of air outlet wind speed distribution, using a hot-wire anemometer to measure at cross-sectional grid points with a grid spacing of 200mm, to check if the standard deviation of wind speed is ≤0.5m / s; S46: The air outlet guide plate is replaced with a precast refractory castable component with a thickness of 150mm. After installation, it is baked and cured at 1100℃, with the baking curve consisting of three stages of temperature increase. S47: Check the material accumulation at the air outlet every shift. When the material accumulation thickness exceeds 50mm, start the air cannon to clean it. Record the cleaning cycle to the DCS system.

[0024] Preferably, the following steps are included when reconstructing the outlet pipe of the denitrification furnace: S51: Modify the top plate of the denitrification furnace outlet to be inclined at 30° to the horizontal plane, process it with a laser cutting machine, and ensure that the bevel angle error is ≤1°. Perform PT testing after welding. S52: The baffle plate at the connection between the outlet and the mixing chamber is replaced with refractory castable, with dimensional accuracy controlled within ±2mm, installation gap ≤3mm, and curing for 72 hours after pouring; S53: Replace the metal spiral wound gasket at the flange connection of the outlet pipe with a 304 stainless steel strip + flexible graphite material, with a compression ratio controlled at 15-20%, and uniform bolt preload; S54: Weld a wear-resistant liner, 8mm thick, made of NM400 wear-resistant steel plate, to the elbow of the outlet pipe. After welding, perform UT testing, with a defect rate ≤0.5%. S55: Monthly inspection of the displacement of the expansion joint of the outlet pipeline; lateral displacement ≤20mm, axial displacement ≤15mm; real-time monitoring using displacement sensors. S56: The insulation layer of the outlet pipeline is made of aluminum silicate fiber blanket with a density of 200kg / m³ and a thickness of 150mm, with an outer protective layer of 0.8mm aluminum plate, and the joints are sealed. S57: Conduct stress analysis on the export pipeline every quarter, using ANSYS software for modeling, and check whether the maximum stress is ≤ 80% of the material's allowable stress. Archive the analysis results.

[0025] Preferably, the air cannon nozzle upgrade includes the following steps: S61: Replace 27 straight nozzles at the inlet and eccentric cone of the denitrification furnace with fan-shaped nozzles, adjust the spray angle to 60°, the flow coefficient Cv=5.0, and the material to be 316L stainless steel; S62: The air cannon's air tank pressure is set to 0.8MPa, and it is equipped with an automatic drain valve. Condensate is drained once per shift, and the drainage volume is recorded in the log. S63: Nozzle installation position error ≤10mm laterally, ≤5mm longitudinally, calibrated using a laser positioning instrument, with the spray direction forming a 30° angle with the material flow direction; S64: Monthly test the nozzle outlet flow rate using an anemometer at a distance of 100mm from the nozzle to check if the flow rate is ≥200m / s and if the flow rate deviation is ≤±5%; S65: Two air cannons are added between the outlet of the tertiary air duct and the outlet of the denitrification furnace, with a spacing of 1500mm and adjustable spray direction. The material is silicon carbide ceramic composite. S66: An air cannon is added to both the eccentric cone straight section and the smoke chamber expansion joint, with the nozzle centerline forming a 30° angle with the pipe wall and a coverage radius ≥ 500mm; S67: Two air cannons are added to the upper conical section of the mixing chamber, which are controlled by solenoid valves with a response time of ≤0.2 seconds and the injection frequency is linked to the material flow rate.

[0026] Preferably, the following steps are included when applying microcrystalline materials in depth: S71: The lining of key components is replaced with a microcrystalline board, 25mm thick, with a flexural strength ≥40MPa and a temperature resistance range ≤1200℃; S72: Microcrystalline panels are installed using a staggered dry-laying method, with joint width controlled at 2-3mm, and filled with high-temperature resistant mortar, which has a temperature resistance of ≥1300℃. S73: Monthly inspection of the surface roughness of the microcrystalline board, using a portable roughness meter to measure whether Ra is ≤0.4, marking worn areas and replacing them first; S74: Establish a wear record for microcrystalline materials, recording the wear amount of each plate. Replace the plate when the thickness loss exceeds 30%, and incorporate the replacement cycle prediction model into the DCS. S75: Microcrystalline board curing adopts a steam curing process, with temperature controlled at 50±5℃, humidity ≥95%, and curing time of 72 hours, divided into three stages of heating and cooling; S76: Operators receive training on the properties of microcrystalline materials, mastering the thermal shock resistance and corrosion resistance performance indicators, with a 100% training pass rate; S77: The anti-scabbing performance of microcrystalline materials will be evaluated quarterly. The effect will be quantified by the scale of the scale and the frequency of cleaning. The evaluation results will be linked to performance appraisal.

[0027] As a preferred option, the intelligent transformation of the pressure measurement system includes the following steps: S81: Install a differential pressure transmitter 500mm above the flap valve, with a range of 0-1000Pa, accuracy of 0.1%FS, signal input to the DCS system, and response time ≤0.5 seconds; S82: The DCS system is configured with three alarm levels: Level 1 alarm 500Pa, Level 2 alarm 700Pa, and Level 3 alarm 900Pa. Alarm information is pushed to mobile terminals. S83: The pressure measuring device shall be calibrated monthly using a standard pressure source at 0%, 50%, and 100% of the measuring range for three-point verification. The error shall be ≤0.2%FS, and the calibration record shall be archived. S84: The pressure testing pipeline uses φ12×2mm stainless steel pipe with a slope of ≥5%. A drain valve is installed at the lowest point, and the draining cycle is once a day. The draining volume is recorded in the log. S85: Operator training will enable them to master pressure trend analysis skills and determine the location of material blockage through pressure curves. The training content includes case analysis and practical operation. S86: Establish a historical database of pressure data, with a sampling period of 1 second, a storage period of ≥1 year, and data backup to a cloud server; S87: Develop pressure data analysis software to achieve material blockage early warning and fault diagnosis functions, with an early warning accuracy rate of ≥95% and automatic generation of diagnostic reports.

[0028] Preferably, when expanding or upgrading a ventilation system, the following steps are included: S91: The cross-sectional area of ​​the denitrification furnace outlet pipe is increased from 0.5m² to 0.7m², and it is machined using a CNC bending machine with an ovality ≤1%. After welding, it undergoes PT testing with a defect rate ≤0.5%. S92: After the modification of the tertiary air duct outlet, the ventilation area increased to 1.2m², the wind speed was controlled at 8-12m / s, the air volume adjustment range was ±10%, and a variable frequency fan was used for control; S93: The total ventilation volume of the system is increased to 180,000 m³ / h, equipped with a variable frequency fan to achieve stepless air volume adjustment, with a fan efficiency of ≥85% and noise level of ≤85dB; S94: Monthly system resistance testing, using a Pitot tube at a measuring point grid with a grid spacing of 500mm, the total resistance is ≤4500Pa, and the resistance distribution is uniform; S95: The interior of the ventilation duct is polished to a surface roughness of Ra3.2 to reduce material adhesion. After polishing, a cleanliness test is performed, and particulate matter residue is ≤0.1g / m². S96: Install an air volume regulating valve with an opening control accuracy of ±2% to achieve balanced air volume distribution in each branch. The regulating valve actuator uses an electric actuator with a response time of ≤2 seconds. S97: Conduct CFD flow field simulations every quarter to optimize pipeline layout, eliminate low-speed vortex regions, and compare simulation results with actual measurement data with an error of ≤5%.

[0029] Preferably, the dynamic optimization of process parameters includes the following steps: S1001: Establish an operating parameter database to record key parameters such as air volume, temperature, and pressure. The sampling period is 1 minute, and the data is stored in a real-time database. Historical data is retained for ≥3 years. S1002: Develop an expert control system that automatically adjusts operating parameters based on changes in material composition and output, with an adjustment range of ≤±5% and a system response time of ≤30 seconds; S1003: Perform thermal calibration monthly, measuring system thermal efficiency, unit energy consumption, and other indicators. The thermal efficiency target is ≥85%, and the unit energy consumption is ≤105kJ / kg. The calibration report shall be submitted to management. S1004: Operators receive training on dynamic parameter adjustment, mastering the skill of adjusting the feed rate according to pressure changes. The training includes simulation exercises and practical assessments, with a 100% pass rate. S1005: Establish a crusting early warning model, and achieve early intervention through multi-parameter coupled analysis of temperature, pressure and composition, with an early warning lead time of ≥1 hour and an accuracy rate of ≥90%; S1006: Conduct system capability testing quarterly to verify operational stability under 120% load conditions, with key parameter fluctuations ≤ ±3%, and archive test reports; S1007: Benchmark against leading companies in the industry, continuously improve operating procedures, and enhance system reliability.

[0030] Example 1 Background: A Shaanxi cement company has long faced the following problems in the operation of its denitrification furnace system: (1) Severe scaling: Material adhesion is frequent in high-temperature scaling areas, resulting in a 30%-40% reduction in pipe cross-sectional area and an increase in system resistance; (2) Unplanned shutdowns: Rotary kiln shutdowns due to scaling blockage occur an average of 9 times per year, with a single shutdown loss of about RMB27,000; (3) Limited production capacity: The clinker hourly output is only 150 t / h, the free calcium qualification rate is 89.7%, and the clinker three-day strength compliance rate is 93.3%, which is lower than the industry average; (4) High energy consumption: The system thermal efficiency has not reached the optimal level, and there is room for optimization of unit energy consumption.

[0031] Implementation steps: S1101: Increase the inner diameter of the feed pipe from 1000mm to 1200mm, maintain the pipe wall thickness at 8mm, and ensure the inner wall roughness is ≤Ra0.8, thereby increasing the material throughput capacity to 120% of the design flow rate; S1102: A 20mm thick microcrystalline plate (surface roughness ≤ Ra0.4) is laid on the 300mm pipe section below the expansion joint, and the joints are filled with high-temperature resistant mortar to replace the original 304 stainless steel lining; S1103: A DN50 interface is reserved 150mm above the expansion joint, and a 316L stainless steel fan-shaped nozzle (spray angle 60°, Cv=5.0) is installed to automatically clean the scale in conjunction with a laser rangefinder (alarm threshold pipe diameter 70%). S1104: Adjust the inclination angle of the feed pipe to 22° (error ≤ ±1°), and verify the material flow velocity ≥ 0.8m / s using a laser level; S1105: Cut the spare feed pipe and secondary feed valve, weld a 10mm thick sealing plate and perform 100% X-ray inspection (defect rate ≤1%); S1106: Move the denitrification furnace feeding box upward by 1000mm, increase the vertical distance between the feeding point and the distribution valve to 800mm, and adjust the feeding plate angle from 5° to 25° to improve the material dispersion effect; S1107: The section of pipe below the flap valve of the denitrification furnace feed pipe from C4 is laid with microcrystalline plates using a staggered dry-laying method (joints 2-3mm, installation gap ≤3mm), replacing the original refractory brick lining; S1108: Equipped with two pressure sensors (range 0-5000Pa, accuracy ±0.2%FS), the signals are connected to the DCS system to achieve real-time monitoring of the material feeding condition; S1109: The air outlet was changed from a φ800mm circular shape to a flat structure with a width of 1200mm and a height of 400mm, increasing the ventilation area by 40% and controlling the wind speed at 8-12m / s; S1110: The bottom is chamfered at 45° (R=100mm) and machined using a CNC plasma cutting machine (surface roughness ≤Ra3.2) to eliminate the low-speed eddy current zone; S1111: Two Hastelloy C276 air cannons (nozzle spacing 500mm, spray angle ±15°) are symmetrically installed at 1 / 3 height of the air outlet to achieve dynamic cleaning in conjunction with monthly wind speed distribution monitoring (standard deviation ≤0.5m / s); S1112: Replace the original horizontal top plate with a 30° inclined structure (bevel error ≤1°), perform PT testing after welding, and replace the original horizontal top plate; S1113: The baffle plate at the connection between the outlet and the mixing chamber is replaced with a precast refractory castable component (150mm thick), which is installed after being baked and cured at 1100℃. S1114: The pipe insulation layer uses a 200kg / m³ aluminum silicate fiber blanket (150mm thick), with an external 0.8mm aluminum plate protective layer to reduce surface heat loss; S1115: Install a 0-1000Pa differential pressure transmitter (accuracy 0.1%FS) 500mm above the flap valve, connect the signal to the DCS and set three alarm levels (Level 1: 500Pa, Level 2: 700Pa, Level 3: 900Pa); S1116: Use φ12×2mm stainless steel pipe (slope ≥5%), drain sewage once a day, and verify three times a month (error ≤0.2%FS) to ensure data accuracy.

[0032] Data comparison table:

[0033] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An optimization method for preventing scaling in a denitrification furnace preheater system used in cement production; characterized in that: It includes the following steps: S11: By increasing the pipe diameter, replacing the lining with high-temperature resistant microcrystalline material, and adding a pressure measuring device, the material throughput capacity is improved and the crusting status is monitored in real time; S12: Remove redundant pipes, adjust the position of the material feeding box, replace the microcrystalline liner, and integrate a DCS with a pressure sensor to achieve visualized control of material feeding efficiency and operating conditions; S13: Reconstruct the cross-sectional shape and airflow guiding structure of the air outlet, add an air cannon array, and coordinate with DCS pressure monitoring to eliminate localized material accumulation and uneven airflow. S14: Optimize the top plate inclination angle and the guide vane material to increase the ventilation cross-sectional area, reduce system resistance, and improve thermal stability; S15: Replaces the straight nozzle with a fan-shaped nozzle, precisely positioning the spray points, and combines solenoid valve control for efficient cleaning of crusted areas; S16: In high-temperature areas prone to skin formation, microcrystalline boards are completely replaced. Through staggered dry-laying technology and wear monitoring, the equipment life is extended and manual intervention is reduced. S17: Deploy differential pressure transmitters and a three-level alarm mechanism, with data directly connected to the DCS for material blockage early warning and dynamic adjustment of process parameters; S18: Increase the cross-sectional area of ​​the pipeline, optimize the flow field distribution, and combine variable frequency fans with CFD simulation to ensure balanced airflow and energy-saving operation of the system; S19: Establish an operational database and expert control system to achieve adaptive adjustment of thermal regime and maximize production capacity through multi-parameter coupling analysis.

2. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: The following steps are included in the structural modification of the eccentric cone feed tube: S21: Increase the inner diameter of the eccentric cone feed pipe from 1000mm to 1200mm to improve the material throughput to 120% of the design flow rate, while maintaining a pipe wall thickness of 8mm and an inner wall roughness ≤ Ra0.8; S22: Remove the original flap valve and expansion joint, and replace them with high-temperature resistant 304 stainless steel. The sealing test requires a leakage rate of ≤0.1L / min at a pressure of 0.5kPa. S23: The inner wall of the pipe section 300mm below the expansion joint shall be covered with a microcrystalline plate with a thickness of 20±2mm and a surface roughness ≤Ra0.

4. The joints shall be filled with high-temperature resistant mortar. S24: A DN50 air cannon interface is reserved 150mm above the expansion joint, and a high-temperature resistant 316L stainless steel fan-shaped nozzle is installed to match it, with a spray angle of 60° and a flow coefficient Cv=5.0; S25: The inclination angle of the feed pipe is adjusted to 22°, with an angle error of ≤±1° with the horizontal plane. A laser level is used for calibration, and the material's self-flow velocity is checked to ensure it is ≥0.8m / s. S26: Install a laser rangefinder to monitor the material accumulation height in the feed pipe in real time, set the alarm threshold to 70% of the pipe diameter, and the data acquisition frequency is 1 time / second; S27: Use an endoscope to check the wear of the tube wall every quarter. Replace the microcrystalline plate immediately when the wear exceeds 5mm, and record the location and extent of the wear.

3. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: The optimization of the C4 feed pipe system includes the following steps: S31: Cut and dismantle the spare feed pipe and secondary feed valve of the mixing chamber, weld the sealing plate with a thickness of not less than 10mm, and perform 100% X-ray inspection after welding, with a defect rate of ≤1%; S32: Move the entire feeding box of the denitrification furnace upward by 1000mm. After adjustment, the vertical distance between the feeding point and the distribution valve is 800mm, and the angle of the feeding plate is adjusted from 5° to 25°. S33: The section of pipe below the flap valve of the denitrification furnace feed pipe from C4 should be replaced with a microcrystalline lining. The joint width should be controlled at 2-3mm, the installation gap ≤3mm, and the staggered dry-laying method should be used for construction. S34: Install one pressure sensor on each of the feed pipes from C4 to the decomposition furnace and the denitrification furnace, with a range of 0-5000Pa and an accuracy of ±0.2%FS. The signal is connected to the DCS system. S35: Check the torque of the flange connection bolts of the feed pipe monthly to ensure that the preload of the M16 bolts reaches 180 N·m, and verify it using a torque wrench; S36: Use compressed air to blow clean the inner wall of the feed pipe weekly, with the pressure controlled at 0.6MPa and the blowing time lasting for 3 minutes, focusing on cleaning the accumulated material at the joints; S37: Adjust the deviation between the center line of the feed pipe and the axis of the denitrification furnace to ≤5mm, and use a theodolite for three-dimensional spatial positioning calibration to check the centering accuracy.

4. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: The following steps are included when carrying out three-stage duct outlet improvements: S41: Change the cross-section of the tertiary air duct outlet from a φ800mm circular shape to a flat structure with a width of 1200mm and a height of 400mm, increasing the ventilation area by 40% and controlling the air velocity at 8-12m / s; S42: The bottom of the air outlet is chamfered at 45° with a chamfer radius R=100mm, processed using a CNC plasma cutting machine, with a surface roughness ≤Ra3.2; S43: Remove the eccentric cone pressure measuring ring, weld and seal it, then perform surface polishing to achieve a roughness of Ra1.

6. The sealing test pressure is 1.5 times the design pressure. S44: Two air cannons are symmetrically installed at 1 / 3 height of the air outlet, with a nozzle spacing of 500mm and an adjustable spray angle range of ±15°. The material is Hastelloy C276. S45: Monthly inspection of air outlet wind speed distribution, using a hot-wire anemometer to measure at cross-sectional grid points with a grid spacing of 200mm, to check if the standard deviation of wind speed is ≤0.5m / s; S46: The air outlet guide plate is replaced with a precast refractory castable component with a thickness of 150mm. After installation, it is baked and cured at 1100℃, with the baking curve consisting of three stages of temperature increase. S47: Check the material accumulation at the air outlet every shift. When the material accumulation thickness exceeds 50mm, start the air cannon to clean it. Record the cleaning cycle to the DCS system.

5. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: The following steps are included when reconstructing the outlet pipeline of the denitrification furnace: S51: Modify the top plate of the denitrification furnace outlet to be inclined at 30° to the horizontal plane, process it with a laser cutting machine, and ensure that the bevel angle error is ≤1°. Perform PT testing after welding. S52: The baffle plate at the connection between the outlet and the mixing chamber is replaced with refractory castable, with dimensional accuracy controlled within ±2mm, installation gap ≤3mm, and curing for 72 hours after pouring; S53: Replace the metal spiral wound gasket at the flange connection of the outlet pipe with a 304 stainless steel strip + flexible graphite material, with a compression ratio controlled at 15-20%, and uniform bolt preload; S54: Weld a wear-resistant liner, 8mm thick, made of NM400 wear-resistant steel plate, to the elbow of the outlet pipe. After welding, perform UT testing, with a defect rate ≤0.5%. S55: Monthly inspection of the displacement of the expansion joint of the outlet pipeline; lateral displacement ≤20mm, axial displacement ≤15mm; real-time monitoring using displacement sensors. S56: The insulation layer of the outlet pipeline is made of aluminum silicate fiber blanket with a density of 200kg / m³ and a thickness of 150mm, with an outer protective layer of 0.8mm aluminum plate, and the joints are sealed. S57: Conduct stress analysis on the export pipeline every quarter, using ANSYS software for modeling, and check whether the maximum stress is ≤ 80% of the material's allowable stress. Archive the analysis results.

6. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: Upgrading the air cannon nozzle includes the following steps: S61: Replace 27 straight nozzles at the inlet and eccentric cone of the denitrification furnace with fan-shaped nozzles, adjust the spray angle to 60°, the flow coefficient Cv=5.0, and the material to be 316L stainless steel; S62: The air cannon's air tank pressure is set to 0.8MPa, and it is equipped with an automatic drain valve. Condensate is drained once per shift, and the drainage volume is recorded in the log. S63: Nozzle installation position error ≤10mm laterally, ≤5mm longitudinally, calibrated using a laser positioning instrument, with the spray direction forming a 30° angle with the material flow direction; S64: Monthly test the nozzle outlet flow rate using an anemometer at a distance of 100mm from the nozzle to check if the flow rate is ≥200m / s and if the flow rate deviation is ≤±5%; S65: Two air cannons are added between the outlet of the tertiary air duct and the outlet of the denitrification furnace, with a spacing of 1500mm and adjustable spray direction. The material is silicon carbide ceramic composite. S66: An air cannon is added to both the eccentric cone straight section and the smoke chamber expansion joint, with the nozzle centerline forming a 30° angle with the pipe wall and a coverage radius ≥ 500mm; S67: Two air cannons are added to the upper conical section of the mixing chamber, which are controlled by solenoid valves with a response time of ≤0.2 seconds and the injection frequency is linked to the material flow rate.

7. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: When applying microcrystalline materials in depth, the following steps are included: S71: The lining of key components is replaced with a microcrystalline board, 25mm thick, with a flexural strength ≥40MPa and a temperature resistance range ≤1200℃; S72: Microcrystalline panels are installed using a staggered dry-laying method, with joint width controlled at 2-3mm, and filled with high-temperature resistant mortar, which has a temperature resistance of ≥1300℃. S73: Monthly inspection of the surface roughness of the microcrystalline board, using a portable roughness meter to measure whether Ra is ≤0.4, marking worn areas and prioritizing replacement; S74: Establish a wear record for microcrystalline materials, recording the wear amount of each plate. Replace the plate when the thickness loss exceeds 30%, and incorporate the replacement cycle prediction model into the DCS. S75: Microcrystalline board curing adopts a steam curing process, with temperature controlled at 50±5℃, humidity ≥95%, and curing time of 72 hours, divided into three stages of heating and cooling; S76: Operators receive training on the properties of microcrystalline materials, mastering the thermal shock stability and corrosion resistance performance indicators, with a 100% training pass rate; S77: The anti-scabbing performance of microcrystalline materials will be evaluated quarterly. The effect will be quantified by the scale of the scale and the frequency of cleaning. The evaluation results will be linked to performance appraisal.

8. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: The intelligent transformation of the pressure measurement system includes the following steps: S81: Install a differential pressure transmitter 500mm above the flap valve, with a range of 0-1000Pa, accuracy of 0.1%FS, signal input to the DCS system, and response time ≤0.5 seconds; S82: The DCS system is configured with three alarm levels: Level 1 alarm 500Pa, Level 2 alarm 700Pa, and Level 3 alarm 900Pa. Alarm information is pushed to mobile terminals. S83: The pressure measuring device shall be calibrated monthly using a standard pressure source at 0%, 50%, and 100% of the measuring range for three-point verification. The error shall be ≤0.2%FS, and the calibration record shall be archived. S84: The pressure testing pipeline uses φ12×2mm stainless steel pipe with a slope of ≥5%. A drain valve is installed at the lowest point, and the draining cycle is once a day. The draining volume is recorded in the log. S85: Operator training will enable them to master pressure trend analysis skills and determine the location of material blockage through pressure curves. The training content includes case analysis and practical operation. S86: Establish a historical database of pressure data, with a sampling period of 1 second, a storage period of ≥1 year, and data backup to a cloud server; S87: Develop pressure data analysis software to achieve material blockage early warning and fault diagnosis functions, with an early warning accuracy rate of ≥95% and automatic generation of diagnostic reports.

9. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: When expanding or upgrading a ventilation system, the following steps are included: S91: The cross-sectional area of ​​the denitrification furnace outlet pipe is increased from 0.5m² to 0.7m², and it is machined using a CNC bending machine with an ovality ≤1%. After welding, it undergoes PT testing with a defect rate ≤0.5%. S92: After the modification of the tertiary air duct outlet, the ventilation area increased to 1.2m², the wind speed was controlled at 8-12m / s, the air volume adjustment range was ±10%, and a variable frequency fan was used for control; S93: The total ventilation volume of the system is increased to 180,000 m³ / h, equipped with a variable frequency fan to achieve stepless air volume adjustment, with a fan efficiency of ≥85% and noise level of ≤85dB; S94: Monthly system resistance testing, using a Pitot tube at a measuring point grid with a grid spacing of 500mm, the total resistance is ≤4500Pa, and the resistance distribution is uniform; S95: The interior of the ventilation duct is polished to a surface roughness of Ra3.2 to reduce material adhesion. After polishing, a cleanliness test is performed, and particulate matter residue is ≤0.1g / m². S96: Install an air volume regulating valve with an opening control accuracy of ±2% to achieve balanced air volume distribution in each branch. The regulating valve actuator uses an electric actuator with a response time of ≤2 seconds. S97: Conduct CFD flow field simulations every quarter to optimize pipeline layout, eliminate low-speed vortex regions, and compare simulation results with actual measurement data with an error of ≤5%.

10. The method for optimizing the anti-scaling of a denitrification furnace preheater system for cement production according to claim 1, characterized in that: The following steps are included when dynamically optimizing process parameters: S1001: Establish an operating parameter database to record key parameters such as air volume, temperature, and pressure. The sampling period is 1 minute, and the data is stored in a real-time database. Historical data is retained for ≥3 years. S1002: Develop an expert control system that automatically adjusts operating parameters based on changes in material composition and output, with an adjustment range of ≤±5% and a system response time of ≤30 seconds; S1003: Perform thermal calibration monthly, measuring system thermal efficiency, unit energy consumption, and other indicators. The thermal efficiency target is ≥85%, and the unit energy consumption is ≤105kJ / kg. The calibration report shall be submitted to management. S1004: Operators receive training on dynamic parameter adjustment, mastering the skill of adjusting the feed rate according to pressure changes. The training includes simulation exercises and practical assessments, with a 100% pass rate. S1005: Establish a crusting early warning model, and achieve early intervention through multi-parameter coupled analysis of temperature, pressure and composition, with an early warning lead time of ≥1 hour and an accuracy rate of ≥90%; S1006: Conduct system capability testing quarterly to verify operational stability under 120% load conditions, with key parameter fluctuations ≤ ±3%, and archive test reports; S1007: Benchmark against leading companies in the industry, continuously improve operating procedures, and enhance system reliability.

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