摘要 |
The present invention relates to an immersed heat transfer tube installed in a fluidized bed of a fluidized-bed boiler for recovering combustion heat generated when a fuel such as RDF (refuse derived fuel) with high calorific value containing biomass and plastics, or wastes is combusted. An immersed heat transfer tube (5) which is installed in a fluidized bed (3) of a fluidized-bed boiler (1) includes a water tube (6) through which a fluid flows, a cylindrical protector (8) provided at an outer circumferential side of the water tube (6) and configured to protect the water tube (6), and a packed bed (7) provided between the water tube (6) and the protector (8). |