With using some simplified heat-transfer & combustion model, the burn-out time and the stay-time(one times through furnace) of a single coal particle in the furnace of CFB were also calculated.

The paper introduces a continuous car type furnace for direct reduction of iron ore. Coal-containing iron ore pellets are laid on cars and carried to pass through furnace to be heated and reduced.

We can only go through some fires with a large faith; little faith will fail. We must have the victory in the furnace.