a coal feed system for use in a fluidized bed combustor in which a grate is supported in a housing and is adapted to support a bed of particulate material including a combustible fuel . air is passed through the grate and into the bed to fluidize the particulate material . the particulate fuel material is separated externally of the bed into a relatively coarse material and a relatively fine material . the fine material is agglomerated and it , along with the coarse material , is passed to a distributor which distributes the material onto selected areas extending across the upper surface of the bed .