This paper presents an experimental study of heat transfer between a shallow fluidized bed and the surface of a single horizontal tube and a tube bundle, which is immersed in it.
Carbon, which is prepared from the Date stones, is used as a solid to be fluidized and a compressed air as an external fluid.
The results showed that the overall heat transfer coefficient of tubes bundle, which immersed in fluidized bed is lower than single tube.
The modified correlations and analysis are offered by experimental work, which shows the relations between heat transfer coefficient and superficial mass velocity.

Key word: heat transfer - heat exchangers - fluidized bed heat exchangers