(Basic knowledge) Can cyclone fluidized bed boilers experience \"deflagration\"?
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Can circulating fluidized bed boilers experience \"deflagration\"?
Compared to coal-fired pulverized fuel boilers, circulating fluidized bed boilers are less likely to experience deflagration or explosion. However, due to multiple restarts and ignitions during actual operation, a large amount of flammable materials accumulate. If proper purging and adequate ventilation are not carried out, deflagration and explosion can also occur. Therefore, in our actual work, we must avoid any complacency and must operate strictly in accordance with the Regulations to prevent deflagration and explosion.
Compared to coal-fired pulverized fuel boilers, circulating fluidized bed boilers are less prone to deflagration and explosion. But if it is restarted and ignited multiple times, a large amount of flammable materials will accumulate. If proper purging and adequate ventilation are not carried out, deflagration and explosion can also occur.
Yes, especially during emergency shutdowns or when the furnace is shut down, if the fans are not restarted in accordance with the operating procedures, flammable gases can be generated as a result of incomplete combustion of coal, leading to explosions. It often appears in the tail flue ducts and air ducts, as well as inside the furnace; our company has encountered this issue twice!
1. If the fuel contains too much moisture and has a low calorific value, continuing to feed it in when the bed temperature drops sharply generates large amounts of non-flammable gases. When these gases reach their explosive concentration limit, an explosion occurs; in severe cases, this can damage the furnace walls or the equipment in the rear flue ducts, such as economizers, air preheaters, or explosion-proof doors. 2. Improper operation during fire suppression led to an accumulation of large amounts of fuel in the furnace, generating a significant quantity of non-flammable gases; when oxygen was introduced suddenly upon restarting the fire, intense combustion occurred resulting in an explosion.