A fluidized bed heat exchanger with a chamber (24) comprises a solid particles inlet port (22), a solid particles outlet port (30), arranged at a distance to the inlet port (22), means (46) for introducing a fluidizing gas from a bottom area into the chamber (24). The heat exchanger has furthermore several heat exchange tubes (28) being arranged at a distance to each other. The heat exchange tubes (28) are each arranged in a meandering fashion and a wall-like pattern and extend substantially parallel to the main flow direction of the solid particles on their way to and through the outlet port (30).