Coal ignition characteristics in CFB boiler

The coal ignition temperature in CFB boilers is an important parameter for designing the startup burner and for choosing operating method during the startup process. The combustion of seven different types of coal were measured in a laboratory scale fluidized bed with under-bed preheat system. The study analyzed the effects of particle size, furnace temperature, volatiles content and moisture content on the ignition temperature, TiF. TiF in the fluidized beds were measured at standard operating conditions. Comparison of the ignition temperatures and the feed temperatures in real CFB boilers shows that the TiF measured in fluidized beds can be used as a reference for the coal feeding process.