Phenomenon:
--- The difference between the temperature indication of one or several thermocouples and the average value is relatively large (the difference is larger than 100℃).
--- Under the premise that the bed pressure is normal, the pressure of air box increases.
--- One or several bed pressure indication is the static reading, not the fluctuation readings during the normal operation.
--- There is white sparks in the bed, and the coking blocks can be seen form the peephole, and the load is difficult to be carried if the coking is serious.
--- The boiler bed temperature is too high or the melting point of the bed material is too low.
--- During the boiler operation, the ratio between the air and coal is not appropriate for a long time.
--- Before starting, there is a lot of clogging inside of the fluidization air nozzle. Or there is debris left in the furnace, just like the refractory material.
Treatment:
--- The primary air flow should be increased.
--- Reduce the bed temperature appropriately. Note that the rising rate of bed temperature should not be too large especially when the material is fed.
--- If there is no improvement after the adjustment, stop the boiler immediately.