Intra-layer heat transfer tube of the fluidized bed boiler

The present invention relates to intra-layer heat transfer tube installed in the fluidized bed of the fluidized bed boiler for recovering high heating value of RDF (Refuse Derived Fuel) or waste fuel is burned in the combustion heat containing biomass and plastic it is intended. Intra-layer heat transfer tube of the fluidized bed boiler, in a fluidized bed (3) intralayer heat transfer tubes disposed within the fluidized bed boiler (1) (5), inner-layer heat transfer tube (5), the fluid flow inside water pipe (6), the water pipes provided on the outer peripheral side of the water pipe (6) and (6) a protector (8) to protect the water pipe (6) and the filling layer provided between the protector (8) (7) composed of a.