Incident Handling 1: What types of failures have occurred with the coal feeding fans of the circulating fluidized bed boilers in your plant?

Common faults of the coal feeding fan in circulating fluidized bed boilers include: ① Due to the high inlet air temperature, the temperatures of the bearings in the coal feeding fan are relatively high, and these bearing temperatures can easily exceed the allowable limits, causing the fan to trip； ②The fan trips when the bearing vibration level exceeds the specified value ； ③Due to the relatively high pressure of the coal feeding air, the fan is prone to operating under overload, causing the motor coils to reach excessive temperatures and resulting in a trip. When the coal feeding fan in a circulating fluidized bed boiler experiences the aforementioned faults, the bypass valve of the coal feeding duct should be opened first to ensure a normal amount of air for coal feeding. If the air volume is insufficient, operation at reduced load or with the furnace under pressure and in standby mode should be adopted to prevent uneven bed temperature or localized excessively high bed temperatures that could lead to coking. Then, carefully inspect the coal feeding fan, identify the cause as soon as possible and take appropriate actions; if it is confirmed that the fan is damaged, it should be repaired promptly to prevent the incident from worsening or causing damage to other equipment.