1. Fire-bed combustion boiler: mainly used in industrial boilers, including fixed grate furnaces, reciprocating grate furnaces, etc.; 2. Fire chamber combustion boilers: mainly used in power station boilers, boilers burning liquid fuel, gaseous fuel and pulverized coal Both are fire chamber combustion boilers; 3. Boiling furnace: The air flow rate sent to the grate is high, so that large particles of coal are tumbling in the boiling bed above the grate, and small particles of coal are rising and burning with the air.