**5. Conclusions**

In an experimental equipment for drying particles in a fluidized bed, this research carries out experimental studies on the fluodynamic behavior of wet forest biomass particles suspended with a flow of hot gas in a fluidized bed with a mechanical stirrer. In addition, the biomass drying process and the heat and mass transfer mechanisms at the gas-particle interface are analyzed.

It is shown that the agitation has an important effect on the biomass particle aerodynamics if the particles have high moisture contents. The effect of the agitator is not relevant when fluidizing low moisture particles.

A methodology for the calculation of the biomass particle surface area is proposed based on Ergun equation. For the prediction of the *Umf* velocity, a new correlation is also proposed, which allows fitting the experimental values with 15% deviations in the predictions of *Umf* for dry as well as wet particles.

*Experimental Investigation on Drying of Forest Biomass Particles in a Mechanically… DOI: http://dx.doi.org/10.5772/intechopen.113973*

On the other hand, the convective heat transfer coefficient between the gas and the solids was experimentally determined, varying between 13 and 25.7 W m<sup>2</sup> K<sup>1</sup> . Based on a mass balance and on the experimental determination of the drying rates, the mass transfer coefficient was obtained, which varied between 6 <sup>10</sup><sup>3</sup> and <sup>20</sup> <sup>10</sup><sup>3</sup> m s<sup>1</sup> .

Thus, a correlation between the Nusselt number and the Reynolds number is proposed for the calculation of the heat transfer coefficient and a correlation between the Sherwood number and the Reynolds number for calculations of the mass transfer coefficient.
