For fine powders, or heat sensitive products, heat input supplied by fluidization gas is low due to low gas velocity,or low gas temperature. Therefore the fluidization surface would be quite important in case of using only air for energetic supply. The use of internal heat exchangers will reduce noticeably this surface because it is proved that the heat transfer coefficient, between particles and an heat exchanger is high according to the level of temperature or the fluidized product. Typical height of product layers are located between 600 to 2500 mm. One of the advantages of the Fluid Bed with Internal Heat Exchangers is that the quantity of exhaust gases is reduced.