Methods for the calculation of heat and mass transfer coefficients based on experimental data are presented, with special regard to gas mixing (back-mixing) conditions. Changes in the voidage of fluidised bed vs. linear gas and height of the fluidisation chamber are shown in diagrams. Heat and mass transfer coefficients are calculated considering the so-called ＇＇driving force＇＇ as determined in several ways. Results are presented in Tables. In the calculations, gas back-mixing was also considered, as determined by analogies between conventional fluidised and rotary fluidised beds.