Abstract: Fluidized bed heat exchanger with a chamber (24), comprising at least one solid particles inlet port (22) at least one solid particles outlet port (30), arranged at a distance to the at least one inlet port (22), means (46) for introducing a fluidizing gas from a bottom area (24b) of said chamber (24) into said chamber (24), wall-like heat transfer means (28) in its lower part, extending in a main flow direction of the solid particles on their way from the inlet port (22) to the outlet port (30), substantially parallel to each other, with a space (C) between adjacent heat transfer means (28), at least one baffle (50,52) in its upper part, extending substantially perpendicular to the heat transfer means (28), downwardly from a chamber ceiling (24c), with its lower end at a distance to the heat transfer means (28) and comprising extensions (E), protruding into the space (C) between adjacent heat transfer means (28), and couplings (B) to mechanically connect the said heat transfer means (28) to said extensions (