In the industrial boiler system, the air pre – heater is a key component for improving combustion efficiency and reducing energy consumption. The air pre – heater equipped by Hanyu Boiler has excellent performance. Standardized use and scientific maintenance are of great significance for its efficient operation and life extension.
I. Specifications for Startup and Shutdown Operations
1. Pre – startup Preparation
Before starting the Hanyu Boiler, start the air pre – heater first. Conduct a comprehensive inspection to ensure there are no foreign objects inside. Start the auxiliary drive motor and let the pre – heater rotate at a low speed for several turns, listening for any abnormalities. Confirm that the oil levels of the guide and thrust bearings are normal, the oil temperature is ≤ 55°C, and the cooling water circulation of the lubrication system is smooth. Otherwise, manually start the oil pump to cool down. Ensure that the oil level of the speed reducer meets the standard, all sealing clearances are adjusted properly, the hot – end radial seal control system is adjusted to the upper limit, and the soot – blowing, cleaning pipelines, instruments, control, and power circuits are normal.
2. Key Points of Shutdown Operations
After the boiler is extinguished, the air pre – heater cannot be stopped immediately. It needs to continue running for heat dissipation to prevent overheating and deformation of the heating surface. When closing the flue damper for short – term hot standby, pay attention to the flue gas inlet and air outlet temperatures to prevent fire. For long – term shutdown, blow soot at least twice before stopping the boiler. After the burners are stopped, let the pre – heater run until the outlet temperature is < 150°C before stopping. After the pre – heater is shut down, when the temperatures of the guide and thrust bearings are < 45°C, stop the oil circulation and cooling water. When the fans are running or stopped, monitor the flue gas and air outlet and inlet temperatures respectively to prevent the pre – heater from catching fire.
II. Precise Monitoring of Operating Parameters
1. Strict Temperature Control
Closely monitor the inlet and outlet temperatures of the air pre – heater. The inlet air temperature should be within the designed range. If it is too low, it is prone to low – temperature corrosion; if it is too high, it will affect the service life. The outlet temperature reflects the pre – heating effect. When it is abnormal, check for ash accumulation or structural problems. During normal operation, the temperatures of the guide and thrust bearings are < 55°C.
2. Real – time Pressure Monitoring
Monitor the changes in inlet and outlet pressures in real – time. If the pressure difference continues to increase and regular soot – blowing is ineffective, the regenerative elements may be blocked, and cleaning should be carried out in a timely manner. During operation, ensure the pressure stability of all parts to avoid interfering with combustion.
3. Reasonable Flow Regulation
Adjust the air flow rate reasonably according to the boiler load and combustion requirements. When the working conditions change, such as fuel type and load adjustment, adjust the flow rate accordingly to keep the pre – heater in the best operating state.
III. Key Measures for Daily Maintenance
1. Efficient Ash Removal
Combustion soot and dust are likely to accumulate in the pre – heater, affecting heat exchange. Regularly clean it with the soot – blowing device in daily use. Initially, perform it once every 24 hours, and then adjust according to the ash – accumulation rate. When the fuel changes, the boiler starts or stops, or the load is < 50%, strengthen soot – blowing to once every 4 – 8 hours. The inlet air temperature can be increased to prevent dew – point ash – accumulation at the cold end. When the smoke – air resistance due to serious ash – accumulation is 686 – 980Pa higher than the design value, shut down the boiler for a comprehensive cleaning. During cleaning, start the auxiliary drive motor to let the pre – heater rotate at a low speed, adjust the hot – end sector plate to the upper limit. After the flue gas flow temperature is < 200°C, close the flue gas and air inlet and outlet dampers, empty the ash in the bottom ash hopper, and open the drain holes. Give priority to using warm water at 60 – 70°C with a pressure of 0.59MPa. If there is no warm water, use normal temperature water and clean with multiple pipes simultaneously. If the deposits are hard, stop the water for half an hour to soften them. For acidic deposits, caustic soda can be added. After cleaning, use the boiler’s waste heat to dry the heating surface for at least 4 – 6 hours to prevent damp corrosion.
2. Tight Sealing Inspection
Regularly inspect the seals of all parts, including radial, axial, bypass, rotor central tube, and static seals. Poor sealing leads to cold air leakage, reducing the pre – heating effect and increasing energy consumption. If the sealing strips or sealing surfaces are found to be damaged or aged, replace them in a timely manner. A smoke tester can be used to find the leakage points.
3. Careful Component Maintenance
According to the equipment manual, regularly add or replace the lubricating grease and lubricating oil for bearings and transmission components to ensure smooth operation. Check the operating condition of the motor to detect potential faults in a timely manner. The cold – end heat – transfer elements are prone to low – temperature corrosion and can be designed separately from the hot and middle sections for easy maintenance and replacement. During daily inspections, check the equipment shell and pipeline connection parts, and handle any problems found in a timely manner. Hanyu Boiler is committed to providing users with high – quality products and services. Correctly using and maintaining the air pre – heater can ensure the efficient and stable operation of the boiler and save costs. If you have any questions or needs, please feel free to contact the professional team of Hanyu Boiler.
