ARRANGEMENT AND METHOD IN BOILER USING FLUIDIZED-BED TECHNOLOGY

An arrangement and method in a boiler using fluidized-bed technology. The arrangement comprises a first space (1) of a furnace that comprises means for forming a fluidized bed (21), a second space of the furnace that does not comprise means for forming a fluidized bed, means for feeding fuel into the first space (1) of the furnace, a partition wall (3) that is at least mainly vertical and arranged between said spaces (1, 2) of the furnace to separate them from each other, the arrangement further comprising a roof structure (5) arranged above the first space of the furnace to separate the first space (1) of the furnace from parts of the second space (2) above it, the first space (1) of the furnace being connected to the second space (2) through a flow path (18), which flow path (18) is arranged on the side of the first space (1) of the furnace to lead gases (G) rising from the fluidized bed to the second space (2) of the furnace.