The study explored the heat transfer properties in an air-fluidized bed of sand, heated with an immersed
heat transfer tube positioned at several angles of inclination. Operating with fluidizing velocity up to
0.5 m/s; and particles of 150–350 lm diameter, the effect of air velocity and particle size on the average
and maximum achieved heat transfer coefficient was examined for the heat transfer tube at angles of
inclination in the range 0–90.